Very impressive work, by a team led by Mark Linehan of IBM Research, on Date Time was presented by NIST’s Ed Barkmeyer at OMG this week. This is a “work in progress” for likely completion later this year but clearly could play an important role in temporal operations in event processing.

To quote from the latest draft, the objectives of this work are:

1. Provide a Standard Business Vocabulary for Date and Time Concepts. Provide a vocabulary of date and time concepts that business users can share and exploit in their business domain vocabularies and rules…
2. Support Machine Reasoning about Time. Provide a formal ontology that enables machine interpretation and reasoning…
3. Enable implementation…

It covers a time infrastructure (intervals, Allen Relations, durations and SBVR “states of affairs” such as events and situations), organizing time in calendars, “indexical time concepts” such as the meaning of “now” etc in a business context, and so forth. Indeed it seems the only thing NOT covered are the ad hoc adjustments of “leap seconds” to a “year” that are made every now again. And there are versions for UML, SBVR and CLIF, and plans an ODM / OWL version.

Just saw some news on Sir Tim Berners-Lee making the case against “closed web solutions” like Facebook, LinkedIn, and even Apple. Basically these companies take your data and use it for your and their own purposes. As opposed to the W3C’s semantic web ideal of having all data available for all to use as needed. Of course, this is where the idealistic “semantic web” was always doomed: data and information has value and therefore is not going to be made freely available, especially where the value of the collecting application is in the use of said data (e.g. Facebook). On the other hand there is much to agree with in this essay - it should be compulsory reading for politicians considering meddling with the internet.

Meanwhile, the value of “semantics” and “web” as separate entities continue to be recognised by most of us. And on the former topic, I see the CallForPapers covering “realtime and continuous semantics”, “rules”, “reasoning and inference” and so forth is up on the 2011 Semantic Technology Conference site. I wonder if organisor Tony Shaw will get some “Semantic CEP” submissions - whether from Facebook, Google, Microsoft, or anyone else…

This might seem an odd question, but there are 2 schools of thought here:

1. An event is a point in time.
   
2. An event is an activity that can take a period of time.

Taking the latter view, we can say things like:

• Earthquake MMM took place from date-time D1 to date-time D2
• Fraudulant act on account NNN took place from date-time D3 to date-time D4
• Flight QQ123 was delayed in the period date-time D3 to date-time D4, when it completed disembarkation time T1 late
• World War 2, an historical event, took place from 1 September 1939 to 2 September 1945.

The problem with this view is that activities, and therefore processes, can therefore be viewed as “events”, which in IT terms can lead to confusion and generalisation. And what about “historical events” like World War 2, which definitely have a duration. But in reality “world war” was a “state” the various nations affected found themselves entangled in - for sure it had a start event (invasion of Poland) and an end event (surrender of Japan), and many many events in between. And indeed many many “predictor events” (or even “causal events”) beforehand.

In event processing terms, we want to predict certain events - when will Earthquake MMM start, and with what strength? - as well as states - Flight QQ123 is now in a “delayed” state. In effect, in the real world, we are concerned not just with event patterns, but also state management and processing. Passengers might not care about the events that lead to their flight being delayed, but they may certainly care about being delayed!

The EPTS Glossary specifies events as points in time as “instantaneous events”. From the EPTS perspective, the 1929 Stock Market Crash was a complex event. At the time it was a “crashing state” for the Wall Street markets - within a period of instability, local rises interspersed with sharp falls. Top-to-bottom, the period covered Sept 1929 to July 1932, and an overall 89% decline in the Dow.

So perhaps History should be formalised, as a science, using event terminology?

Prof. Adrian Paschke has posted the presentation made by himself, Prof. Harold Boley and myself on Semantic Complex Event Processing at SemTech this year (previously blogged about here and here) - and makes an interesting comparison with a prior public presentation in this area 2 years ago. Semantics in CEP were also one of the research topics at DEBS this year, too…

UPDATE: I’ve had a few requests for non-slideshare versions - so here is the PDF .

Elisa Kendall from Sandpiper and Dr Mohammad Ketabchi from Progress were my honorable partners on the Semantic CEP Panel at SemTech today. Q&A covered some interesting questions:

- isn’t the event pattern - decision - reaction view too simplistic?

This was complaint about the “simplified view of the world” slide I presented. Of course, being “simplified” it did not cover, for example, possible multiple levels of abstraction or feedback loops, while learning and update mechanisms are certainly still applicable.

- managing explosion of outgoing events - won’t reaction events potentially overwhelm an event bus?

Usually CEP is “reducing” numbers of simple events (observations etc) into a fewer number of complex / business events - so while this could be a problem, it tends not to be in most practical applications and/or can be managed through the middleware layer.

- what next for financial event processing?

Increased regulatory compliance rules will be applied to more financial operations and transactions by both banking and government agencies… probably a growth area for CEP technologies!

- surely semantic is not just limited to “static” ontology definitions - consider for example ontologies of actions and events?

This was against in introductory slide showing semantic community focus with the “FOAF” type logical relationships - good for text search problems and such, but less so for business operations and behavior - processes and services… Elisa also commented that dynamic classification was certainly a semantics capability, but was more a research topic in “government applications” rather than a productised capability right now.