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<span style="" lang="EN-US">Dear Ilkay,<o:p></o:p></span>
<br>
<span style="" lang="EN-US"><o:p> </o:p></span>
<br>
<span style="" lang="EN-US">Here some
feedback about the Kepler experience we made out of our projects:<o:p></o:p></span>
<br>
<span style="" lang="EN-US"><o:p> </o:p></span>
<br>
<span style="" lang="EN-US">- The
context<o:p></o:p></span>
<br>
<span style="" lang="EN-US">- The
beginning<o:p></o:p></span>
<br>
<span style="" lang="EN-US">- Kepler
installation<o:p></o:p></span>
<br>
<span style="" lang="EN-US">- </span><span style="" lang="EN-GB">Current
functionalities/actors in
Kepler:</span><span style="" lang="EN-US"><o:p></o:p></span>
<br>
<span style="" lang="EN-GB">- Implementing
new actors:<o:p></o:p></span>
<br>
<span style="" lang="EN-GB">- Performance:<o:p></o:p></span>
<br>
<span style="" lang="EN-GB">- Thin
Versus Rich client<o:p></o:p></span>
<br>
<span style="" lang="EN-GB">- Conclusion<o:p></o:p></span>
<br>
<span style="" lang="EN-US"><o:p> </o:p></span>
<br>
<span style="" lang="EN-US">- The
context:<o:p></o:p></span>
<br>
<span style="" lang="EN-US">I am
currently working at the <st1:place w:st="on"><st1:PlaceName
w:st="on">German</st1:PlaceName> <st1:PlaceName w:st="on">Research</st1:PlaceName>
<st1:PlaceType w:st="on">Center</st1:PlaceType></st1:place>
for Artificial Intelligence on different projects where we are using
Kepler to
process Spatial Information (Maps in Vector Information). More
information on
my Blog: <a class="moz-txt-link-freetext" href="http://ctuot.twoday.net/stories/4133335/">http://ctuot.twoday.net/stories/4133335/</a><o:p></o:p></span>
<br>
<span style="" lang="EN-US"><o:p> </o:p></span>
<br>
<span style="" lang="EN-US">Before
going into some Kepler technical specific details, I would like to
explain why
we choose the Kepler platform.<o:p></o:p></span>
<br>
<span style="" lang="EN-US"><o:p> </o:p></span>
<br>
<span style="" lang="EN-US">- The beginning:<o:p></o:p></span>
<br>
<span style="" lang="EN-US">Everything
started with the RAPR project. </span><span style="" lang="EN-GB">RAPR
aims to develop a rule-based prototype to process space-oriented
agricultural knowledge in order to economically grow organic
commodities.<o:p></o:p></span>
<br>
<span style="" lang="EN-GB">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 <st1:country-region
w:st="on"><st1:place w:st="on">Germany</st1:place></st1:country-region>.
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.<o:p></o:p></span>
<br>
<span style="" lang="EN-GB"><o:p> </o:p></span>
<br>
<span style="" lang="EN-GB">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.<o:p></o:p></span>
<br>
<span style="" lang="EN-GB"><o:p> </o:p></span>
<br>
<span style="" lang="EN-GB">Now, let’s
go into some more technical details:<o:p></o:p></span>
<br>
<span style="" lang="EN-GB"><o:p> </o:p></span>
<br>
<span style="" lang="EN-GB">- Kepler
installation:<o:p></o:p></span>
<br>
<span style="" lang="EN-GB">Installing
Kepler is very easy. The couple of examples delivered with the
standard
installation is enough to get quickly started with your own Workflows.<o:p></o:p></span>
<br>
<span style="" lang="EN-GB"><o:p> </o:p></span>
<br>
<span style="" lang="EN-GB">- Current
functionalities/actors in Kepler:<o:p></o:p></span>
<br>
<span style="" lang="EN-GB">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.<o:p></o:p></span>
<br>
<span style="" lang="EN-GB"><o:p> </o:p></span>
<br>
<span style="" lang="EN-GB">- Implementing
new actors:<o:p></o:p></span>
<br>
<span style="" lang="EN-GB">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.<o:p></o:p></span>
<br>
<span style="" lang="EN-GB"><o:p> </o:p></span>
<br>
<span style="" lang="EN-GB">- Performance:<o:p></o:p></span>
<br>
<span style="" lang="EN-GB">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.<o:p></o:p></span>
<br>
<span style="" lang="EN-GB"><o:p> </o:p></span>
<br>
<span style="" lang="EN-GB">- Thin
Versus Rich client<o:p></o:p></span>
<br>
<span style="" lang="EN-GB">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.<o:p></o:p></span>
<br>
<span style="" lang="EN-GB"><o:p> </o:p></span>
<br>
<span style="" lang="EN-GB">- Conclusion<o:p></o:p></span>
<br>
<span style="" lang="EN-GB">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.<o:p></o:p></span>
<br>
<span style="" lang="EN-GB"><o:p> </o:p></span>
<br>
<span style="" lang="EN-GB">If you have
more questions, please do not hesitate to contact me.<o:p></o:p></span>
<br>
<span style="" lang="EN-GB"><o:p> </o:p></span>
<br>
<span style="" lang="EN-GB">Best
regards,<o:p></o:p></span>
<br>
<span style="" lang="EN-GB"><o:p> </o:p></span>
<br>
<span style="" lang="EN-GB">Christopher
Tuot<o:p></o:p></span>
<br>
<span style="" lang="EN-GB"><o:p> </o:p></span>
<br>
<span style="" lang="EN-US"><o:p> </o:p></span>
<br>
-- <br>
______________________________________________________________<br>
Dipl.-Ing. Christopher Tuot<br>
DFKI GmbH (German Research Center for Artificial Intelligence)<br>
Knowledge Management Department<br>
POBox 2080, 67608 Kaiserslautern, Germany <br>
fon: +49(0)631 / 20575 - 127<br>
fax: +49(0)631 / 20575 - 103<br>
mail: <a class="moz-txt-link-abbreviated" href="mailto:christopher.tuot@dfki.de">christopher.tuot@dfki.de</a><br>
web: <a class="moz-txt-link-freetext" href="http://www.dfki.de">http://www.dfki.de</a><br>
______________________________________________________________<br>
Deutsches Forschungszentrum fuer Kuenstliche Intelligenz GmbH<br>
Firmensitz: Trippstadter Strasse 122, D-67663 Kaiserslautern<br>
<br>
Geschaeftsfuehrung:<br>
Prof. Dr. Dr. h.c. mult. Wolfgang Wahlster (Vorsitzender) Dr. Walter
Olthoff<br>
<br>
Vorsitzender des Aufsichtsrats:<br>
Prof. Dr. h.c. Hans A. Aukes<br>
<br>
Amtsgericht Kaiserslautern, HRB 2313<br>
______________________________________________________________
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