Labels:text | screenshot | font OCR: son(se) wmx ) it's has any member docunicht in the time window;" Ïo otherwise; sim( x ) = ") stri( k, e) if c has any member document in the time wind otherwise (b) Figure 3. Determining the modified similarity between a document x and any auster cin the past: [a) the basic for- mula; [b] the formula with an added linear decaying-weight function. i'is the number of documents between x and the most recent member document in c.