Symbol | Definition |
---|---|
y(t) | number of new cases of disease in the t ^{th} week observed in surveillance data |
x(t) | number of new cases of disease in the t ^{th} week predicted by forecasting methods |
x _{ start } | number of new cases of disease predicted at the start of epidemic season |
x _{ peak } | predicted value of the maximum number of new cases of the disease |
e _{ t } | e _{ t }=y _{ t }âˆ’x _{ t } : the prediction error |
T | duration of the epidemic season |
\( \bar {y} \) | \(\bar {y}=\frac {1}{T} \sum _{t=1}^{T} (y_{t}) \) : the mean for y values over T weeks |
Ïƒ ^{2} | \( \sigma ^{2}=\frac {1}{T-1} \sum _{t=1}^{T} (y_{t}-\bar {y})^{2} \) : The variance of y values over T weeks |
n _{ tot } | Total number of infected persons during specified period |
n _{ ps } | The population size at the start of specified period |
n _{ tot }(a g e) | Total number of infected persons with specific age during the specified period |
n _{ ps }(a g e) | The population size with specific age at the start of specified period |
n _{ c } | or n _{ contacts } is the number of contacts of primary infected persons |
n _{ sg } | or n _{ s e c o n dâˆ’g e n e r a t i o n } is the new number of infected persons among the contacts of primary infected individuals during a specified period |
G M{E r r o r} | \( GM(e)= \left (\prod _{i=1}^{n}(e_{i})\right)^{(1/n)} \) : Geometric Mean of a set of Errors |
M{E r r o r} | Arithmetic Mean of a set of Errors |
M d{E r r o r} | Median value of a set of Errors |
R M S{E r r o r} | Root Mean Square of a set of Errors |