Tuesday, January 27, 2009

More on Event Pattern Detection and Discovery


One cannot ignore these days the change of president in the USA, something with affects the entire universe. One minority the Mr. Obama belongs to is the minority of left-handed people, as can be clearly seen in the picture, while four of the last USA presidents were left handed (which make his fifth in the last seven presidents), conference rooms in the USA or university classes - all of them have desks only for the right handed majority. Here is a picture of a left handed desk,
I am sure that the USA president has much more urgent items on his agenda, however, unlike his predecessors he may also do something for the deprived minority of left-handed people. BTW - the situation in Israel (whose current prime-minister is, surprise...a left-handed person) is somewhat better. We, Left handed people may be a small minority (around 10% of the population) but our collective impact on humanity is unproportionately huge -- starting from Alexander the great, Julius Caesar, Napoleon, Queen Victoria, Lewis Carrol, Mark Twain, Escher, Michelangelo, Leonardo da Vinci and many more....well enough of that for now.

Going back to one of my previous posts
that has explained the difference between event pattern detection and event pattern discovery.
In the wake of some questions, here is more about the relationship between these two terms:

  • Event pattern detection is performed for patterns that are known in advance, the pattern detection in done "on-line" when the event occur.
  • Event pattern discovery is performed typically off-line, it can use machine learning techniques on past events in some cases, it can also use some natural language understanding technique to derive pattern from legal documents (e.g. regulations) in other cases.
  • A pattern discovery creates patterns that are detected on-line by pattern detection, so they are complementary techniques.
  • In some cases there is continuous discovery, and thus the patterns are updated in a dynamic way, however, still the discovery feeds the detection part on-line, and the respective roles are preserved.
  • Last but not least, the discovery process may use simulation techniques that use detection of simulated events in order to check assumptions about patterns.
Typically, event processing products contain event pattern detection capabilities, in one form or another. The event pattern discovery is considered as add-on, typically using techniques that are not particular to event processing.

1 comment:

mattlf said...

Great post !
That is what we are doing here at www.alerts4all.com. We use "off line" pattern discovery algorithms to discover trading patterns and then CEP (Esper) to detect them during Market hours.