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A T T E N T I O N: Please note the day, time, and room being
different than usual.<br>
<br>
<br>
I N V I T A T I O N<br>
<font face="sans-serif"> <br>
<br>
to the Research Seminar 'Computer Graphics, Image Processing, and
Visualization'<br>
<br>
</font><font face="sans-serif"> on<font face="sans-serif">
Tuesday, November 24th, 2015, at 3:15 PM,<br>
in Room P-702 in the Paulinum, Augustusplatz.</font><br>
</font><br>
The talk is given by<br>
<br>
Ala Abuthawabeh<br>
Image and Signal Processing Group<br>
Institute of Computer Science<br>
Leipzig University<br>
<br>
and is entitled<br>
<br>
"Multi-Edge Graph Visualizations for Fostering Software
Comprehension".<br>
<br>
Abstract:<br>
<br>
Typically software engineers implement their software according
to the<br>
design of the software structure. Relations between classes and
interfaces<br>
such as method-call relations and inheritance relations are
essential parts<br>
of a software structure. Accordingly, analyzing several types of
relations<br>
will benefit the static analysis process of the software
structure. The<br>
tasks of this analysis include but not limited to: understanding
of<br>
(legacy) software, checking guidelines, improving product lines,
finding<br>
structure, or re-engineering of existing software. Graphs with
multi-type<br>
edges are possible representation for these relations
considering them as<br>
edges, while nodes represent classes and interfaces of software.
Then, this<br>
multiple type edges graph can be mapped to visualizations.
However, the<br>
visualizations should deal with the multiplicity of relations
types and<br>
scalability, and they should enable the software engineers to
recognize<br>
visual patterns at the same time.<br>
To advance the usage of visualizations for analyzing the static
structure<br>
of software systems, I tracked different development phases of
the<br>
interactive multi-matrix visualization (IMMV) showing an
extended user<br>
study at the end. Visual structures were determined and
classified<br>
systematically using IMMV compared to PNLV in the extended user
study as<br>
four categories: High degree, Within-package edges,
Cross-package edges, No<br>
edges. In addition to these structures that were found in these
handy<br>
tools, other structures that look interesting for software
engineers such<br>
as cycles and hierarchical structures need additional
visualizations to<br>
display them and to investigate them. Therefore, an extended
approach for<br>
graph layout was presented that improves the quality of the
decomposition<br>
and the drawing of directed graphs according to their topology
based on<br>
rigorous definitions. The extension involves describing and
analyzing the<br>
algorithms for decomposition and drawing in detail giving
polynomial time<br>
complexity and space complexity. Finally, I handled visualizing
graphs with<br>
multi-type edges using small-multiples, where each tile is
dedicated to one<br>
edge-type utilizing the topological graph layout to highlight
non-trivial<br>
cycles, trees, and DAGs for showing and analyzing the static
structure of<br>
software. Finally, I applied this approach to four software
systems to<br>
show its usefulness. <br>
<font face="sans-serif"><br>
<br>
On behalf of Professor Scheuermann all those interested are
cordially invited to attend.<br>
<br>
<br>
Yours sincerely,</font><br>
<br>
Tom Liebmann
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