A geometric approach to monitoring threshold functions over distributed data streams.

Izchak Sharfman Assaf Schuster Daniel Keren A geometric approach to monitoring threshold functions over distributed data streams. 2007 32 ACM Trans. Database Syst. 4 http://doi.acm.org/10.1145/1292609.1292613 db/journals/tods/tods32.html#SharfmanSK07