Summary of Biosurveillance-relevant statistical and data mining technologies

This is directly applicable to a scalar signal (such as “number of respiratory cases today”. This method, more commonly used in computational finance, simply compares the count during the current time period with the weighted average of the counts of recent days. Exponential weighting is typically used, where the half-life is known as the “time window” parameter. This time-window parameter is typically chosen by hand. Hanning window, a low-pass filter, is another commonly used method for computing the trend of a time series. We prefer the Serfling and Univariate HMM methods described below.