Dear Ilkay, Here some feedback about the Kepler experience we made out of our projects: - The context - The beginning - Kepler installation - Current functionalities/actors in Kepler: - Implementing new actors: - Performance: - Thin Versus Rich client - Conclusion - The context: I am currently working at the German Research Center for Artificial Intelligence on different projects where we are using Kepler to process Spatial Information (Maps in Vector Information). More information on my Blog: http://ctuot.twoday.net/stories/4133335/ Before going into some Kepler technical specific details, I would like to explain why we choose the Kepler platform. - The beginning: Everything started with the RAPR project. RAPR aims to develop a rule-based prototype to process space-oriented agricultural knowledge in order to economically grow organic commodities. Experts in the agricultural domain needed a platform to develop and test their scientific models. An example of model if the Biomass Yield Model (bym) developed by Prof. Piorr and Sybille Brozio at the FH Eberswalde in Germany. The original model has been implemented with the ESRI Product ArcGIS. Developing a model with ArcGIS requires have some strong knowledge in the GIS (Geographic Information System) besides domain specific knowledge, in our case agriculture. The visual programming capabilities of Kepler seamed to be a good approach to allow non-GIS experts to develop and test their models. Therefore we have implemented new actors in Kepler capable of handling most of the standards GIS operations. Now, let?s go into some more technical details: - Kepler installation: Installing Kepler is very easy. The couple of examples delivered with the standard installation is enough to get quickly started with your own Workflows. - Current functionalities/actors in Kepler: The standard library already offers quite a lot of already implemented actors which could suffice for some ?general? problems. For really domain specific usage, you need to implement your own actors. - Implementing new actors: So honestly, implementing new actors is not something you can call easy. There is a documentation about how to check out and configure fisrt Ptolemy (the core of Kepler) and then Kepler itself. Usually, after you checked out from cvs, you need to correct some pieces of code before the whole thing can even compile. Moreover, the number of Jars in the project is amazing and makes it really difficult to keep an overview about the different versions used. I would rather have something like maven and all my jars organized in a nice repository. - Performance: Our workflows usually have up to 15 actors, not more. However, we have processed Gigabytes of data though the workflows. If the actors are implemented correctly, you should not encounter any speed or memory problems. Some of the workflows have ran for days (huge amount of data), without any problems. - Thin Versus Rich client I was bothered by the fact you needed to install the whole Kepler just to be able to edit and execute a workflow. Therefore we have deployed Kepler as a client-server application. The server is a Web-Application in Tomcat and the client is implemented with Adobe Flex 3 (Flash). This allows workflows to be edited and executed in your brother. - Conclusion In my opinion, it is really worth using the Kepler platform. Even though we encountered some problems in the first implementation phase, we quickly managed to get over the few issues and now we are really concentrating on implementing further functionalities. I have already contacted Dr. Ludaescher to see how we can best contribute to the project. If you have more questions, please do not hesitate to contact me. Best regards, Christopher Tuot -- ______________________________________________________________ Dipl.-Ing. Christopher Tuot DFKI GmbH (German Research Center for Artificial Intelligence) Knowledge Management Department POBox 2080, 67608 Kaiserslautern, Germany fon: +49(0)631 / 20575 - 127 fax: +49(0)631 / 20575 - 103 mail: christopher.tuot at dfki.de web: http://www.dfki.de ______________________________________________________________ Deutsches Forschungszentrum fuer Kuenstliche Intelligenz GmbH Firmensitz: Trippstadter Strasse 122, D-67663 Kaiserslautern
Geschaeftsfuehrung: Prof. Dr. Dr. h.c. mult. Wolfgang Wahlster (Vorsitzender) Dr. Walter Olthoff Vorsitzender des Aufsichtsrats: Prof. Dr. h.c. Hans A. Aukes Amtsgericht Kaiserslautern, HRB 2313 ______________________________________________________________ -------------- next part -------------- An HTML attachment was scrubbed... URL: http://mercury.nceas.ucsb.edu/ecoinformatics/pipermail/kepler-users/attachments/20071019/9d5a8c2c/attachment.htm
