STEM FAQ

What is the STEM project release schedule?

Release 0.2.0M1 was being released on June 8th, 2007.

This includes the current STEM source code and down loadable executables for Windows and Linux.

What platforms are supported?

In theory, STEM will run on any platform supported by Eclipse. The current downloads are for RCP versions of Windows and Linux. It has been run on a Mac as well, and a downloadable version for the Mac should be available soon. Note that Java 1.6 is required for MacOS.

If a downloadable RCP version is not available for your platform, you must download the STEM source from CVS and run from the source.

What are the features of release 0.2.0?

The first milestone release includes:

• a full implementation of the STEM graph based simulation engine for spatiotemporal modeling.

• Geographic Visualization of the spread of disease using internally implemented graphics.
• Geographic Visualization of the spread of disease using Google Earth
• "Wizards" to create Projects, Graphs, Models, Scenarios, Sequencers, and Diseases
• Visual Editors to edit Graphs, Models, Scenarios, Sequencers, and Diseases

• a complete data set that defines all of the countries specified by the ISO-3166 standard, this includes area land mass and recent human population data.

• a complete Lat/Long data set in Geography Markup Language (GML) format for all countries defined by the ISO-3166 standard

• an extensive set of predefined "Graph" fragments that can be reused in user Models.
• an extensive set of predefined "Models", one for each country, that can be reused in user Models and Scenarios
• a set of predefined "Scenarios" that illustrate disease spread models around the Earth.
• a predefined SEIR disease model for the Spanish Flu
• deterministic implementations of SI, SIR and SEIR disease models.

What features are planned for future releases?

• Business Intelligence and Reporting Tools (BIRT) integration
• History recording and playback
• Stochastic SI, SIR and SEIR disease models
• New experimental disease models
• Enhanced Editor Functionality (better Drag'n Drop)
• Enhanced Visualizations including multiple views, hover and many bug fixes
• Improvements in the interface (menu layout wizards, etc.)
• Improved documentation
• Improved build environment
• Lot's of bug fixes.

Can STEM be used for more than just disease modeling?

Yes. The core components of STEM implement a graph based spatiotemporal simulation engine. The components that extend it to disease modeling are in separate plug-ins and integrate themselves using Eclipse extension points.

What is the most novel extension to STEM?

The idea of creating a "pandemic game" out of STEM has been discussed by its developers for some time. The basic idea would be to have "players" use their copies of STEM to connect to a central server with a single shared model. The players would make (or not make) decisions based upon their geographic assignment and these would be communicated to the server which would then update and propagate the changes to the model to the distributed player machines.

Can STEM be used for "situational awareness"?

Yes. Basically, one can run a simulation in "real-time" with a Decorator that interfaces to the outside world. That Decorator can access data from outside of the simulation (e.g., from a database or a web service) and then "inject" it into the canonical graph that holds the state of the simulation.

It should be possible to extend STEM to use an existing simulation to initialize other simulations so that one could monitor the world and then spawn off different identically initialized Scenarios that simulate different options given the current world state.