The eLog library was initially developed as a research prototype and later published for lifelogging researchers in 2010 to help them easily analyze heterogenous data and complex visualization. It has been kept growing with the progress of mobile computing environments and recently its UI part is released with GPL v3 license for wider usage. The eLog UI library is optimized for mobile environment and can get easily integrated with existing Web services.

Who We Are

The original work was proposed by Pil Ho and later extended the work with collaboration with 28 researchers around the world who contributed their lifelogs, collaborated for lifelog analysis and share research results to build up an open lifelogging platform for the public. Pil Ho has been keeping the development updating the library following up the progress in mobile computing.


  • Nov. 2014: Change the web page skin using bootstrap.
  • Nov. 2014: Published elog UI library as GPL v3.
  • Oct. 2014: Version up eLog library and documentation.


Reference for Esper + Streaming Sources for CEP

This lab works as the reference to set up user's own CEP environment for lifelog data mining. Specifically we will focus on the use of Esper as the CEP engine and JRuby for stream source generation.

About Esper

Esper is a event stream engine for intelligent complex event processing. Follow the short instruction at here and the full tutorial. For deeper understanding on their event processing language (EPL), look into this reference.


First Experiment

We first tried jRuby as the stremaing sources for Esper testing as desribed at here and its sample code. This handles the case using twitter streams as the source for Esper testing.

Note on Installing Necessary Gems for Tutorial 

sudo jruby -S gem update

sudo JRUBY_OPTS="-Xcext.enabled=true" jruby -S gem install tweetstream


One (Tweetstream) of the ruby gems necessary to run this example was not working well with jRuby 2.0 with a known bug.

Using Twitter Java Client for Streaming 

Our next try was directly using Twitter's Java client interface, hbc. This works well and also the integration with esper was easy too. 

Connecting Esper to Storm