
M. Fink, J.H. Haunert, J. Spoerhase, and A. Wolff. Selecting the aspect ratio of a scatter plot based on its Delaunay triangulation. In Proc. 29th European Workshop on Computational Geometry (EuroCG'13). 2013.
abstract
bibtex

 Scatter plots are diagrams that visualize sets of points in two dimensions. They allow users to detect correlations and clusters in the data. Whether a user can accomplish these tasks highly depends on the aspect ratio selected for the plot, i.e., the ratio between the horizontal and the vertical extent of the diagram. We argue that an aspect ratio is good if the Delaunay triangulation of the scatter plot has some nice geometric property, e.g., a large minimum angle or a small total edge length. In order to find an optimum aspect ratio according to a given criterion we present an algorithm that efficiently maintains the Delaunay triangulation of the point set when traversing all aspect ratios @inproceedings{FinkEtAl2013,
abstract = {Scatter plots are diagrams that visualize sets of points in two dimensions. They allow users to detect correlations and clusters in the data. Whether a user can accomplish these tasks highly depends on the aspect ratio selected for the plot, i.e., the ratio between the horizontal and the vertical extent of the diagram. We argue that an aspect ratio is good if the Delaunay triangulation of the scatter plot has some nice geometric property, e.g., a large minimum angle or a small total edge length. In order to find an optimum aspect ratio according to a given criterion we present an algorithm that efficiently maintains the Delaunay triangulation of the point set when traversing all aspect ratios},
author = {Fink, M. and Haunert, J.H. and Spoerhase, J. and Wolff, A.},
booktitle = {Proc. 29th European Workshop on Computational Geometry (EuroCG'13)},
timestamp = {20130129T14:57:50.000+0100},
title = {Selecting the Aspect Ratio of a Scatter Plot Based on Its {D}elaunay Triangulation},
year = {2013}
}


M. Fink, J.H. Haunert, J. Spoerhase, and A. Wolff. Selecting the aspect ratio of a scatter plot based on its Delaunay triangulation. IEEE Transactions on Visualization and Computer Graphics), 19(12):23262335, 2013.
abstract
doi
bibtex

 Scatter plots are diagrams that visualize twodimensional data as sets of points in the plane. They allow users to detect correlations and clusters in the data. Whether or not a user can accomplish these tasks highly depends on the aspect ratio selected for the plot, i.e., the ratio between the horizontal and the vertical extent of the diagram. We argue that an aspect ratio is good if the Delaunay triangulation of the scatter plot at this aspect ratio has some nice geometric property, e.g., a large minimum angle or a small total edge length. More precisely, we consider the following optimization problem. Given a set Q of points in the plane, find a scale factor s such that scaling the xcoordinates of the points in Q by s and the ycoordinates by 1=s yields a point set P(s) that optimizes a property of the Delaunay triangulation of P(s), over all choices of s. We present an algorithm that solves this problem efficiently and demonstrate its usefulness on realworld instances. Moreover, we discuss an empirical test in which we asked 64 participants to choose the aspect ratios of 18 scatter plots. We tested six different quality measures that our algorithm can optimize. In conclusion, minimizing the total edge length and minimizing what we call the 'uncompactness' of the triangles of the Delaunay triangulation yielded the aspect ratios that were most similar to those chosen by the participants in the test. @article{FinkEtAl2013b,
abstract = {Scatter plots are diagrams that visualize twodimensional data as sets of points in the plane. They allow users to detect correlations and clusters in the data. Whether or not a user can accomplish these tasks highly depends on the aspect ratio selected for the plot, i.e., the ratio between the horizontal and the vertical extent of the diagram. We argue that an aspect ratio is good if the Delaunay triangulation of the scatter plot at this aspect ratio has some nice geometric property, e.g., a large minimum angle or a small total edge length. More precisely, we consider the following optimization problem. Given a set Q of points in the plane, find a scale factor s such that scaling the xcoordinates of the points in Q by s and the ycoordinates by 1=s yields a point set P(s) that optimizes a property of the Delaunay triangulation of P(s), over all choices of s. We present an algorithm that solves this problem efficiently and demonstrate its usefulness on realworld instances. Moreover, we discuss an empirical test in which we asked 64 participants to choose the aspect ratios of 18 scatter plots. We tested six different quality measures that our algorithm can optimize. In conclusion, minimizing the total edge length and minimizing what we call the 'uncompactness' of the triangles of the Delaunay triangulation yielded the aspect ratios that were most similar to those chosen by the participants in the test.},
author = {Fink, M. and Haunert, J.H. and Spoerhase, J. and Wolff, A.},
doi = {10.1109/TVCG.2013.187},
journal = {IEEE Transactions on Visualization and Computer Graphics)},
number = {12},
pages = {23262335},
timestamp = {20130725T18:19:08.000+0200},
title = {Selecting the Aspect Ratio of a Scatter Plot Based on Its {D}elaunay Triangulation},
volume = {19},
year = {2013}
}


J.H. Haunert. An algorithmic approach to geographic information science. Universität Würzburg. Fakultät für Mathematik und Informatik, 2013. Habilitationsschrift (kumulativ).
bibtex

 @phdthesis{Haunert2013b,
author = {Haunert, J.H.},
file = {Haunert_Habil.pdf:http\://www1.pub.informatik.uniwuerzburg.de/pub/haunert/pdf/Haunert_Habil.pdf:PDF},
school = {Fakult\"{a}t f\"{u}r Mathematik und Informatik},
series = {Universit\"{a}t W\"{u}rzburg},
timestamp = {20130725T14:07:36.000+0200},
title = {An Algorithmic Approach to Geographic Information Science},
type = {Habilitationsschrift (kumulativ)},
year = {2013}
}


D. Peng, J.H. Haunert, A. Wolff, and C. Hurter. Morphing polylines based on leastsquares adjustment. In Proc. 16th ICA Generalisation Workshop. 2013.
bibtex

 @inproceedings{Peng2013,
author = {Peng, D. and Haunert, J.H. and Wolff, A. and Hurter, C.},
booktitle = {Proc. 16th ICA Generalisation Workshop},
timestamp = {20130513T17:21:59.000+0200},
title = {Morphing Polylines Based on LeastSquares Adjustment},
year = {2013}
}


Nadine Schwartges, Dennis Allerkamp, J.H. Haunert, and A. Wolff. Optimizing active ranges for point selection in dynamic maps. In Proc. 16th ICA Generalisation Workshop. 2013.
bibtex

 @inproceedings{Schwartges2013,
author = {Schwartges, Nadine and Allerkamp, Dennis and Haunert, J.H. and Wolff, A.},
booktitle = {Proc. 16th ICA Generalisation Workshop},
timestamp = {20130513T17:07:20.000+0200},
title = {Optimizing Active Ranges for Point Selection in Dynamic Maps},
year = {2013}
}


T. C. van Dijk, A. van Goethem, J.H. Haunert, W. Meulemans, and B. Speckmann. Accentuating focus maps via partial schematization. In Proc. 21st ACM SIGSPATIAL International Conference on Advances in Geographic Information Systems (ACM SIGSPATIAL GIS '13), pages 418421. 2013.
abstract
doi
bibtex

 We present an algorithm for schematized focus maps. Focus maps integrate a high detailed, enlarged focus region continuously in a given base map. Recent methods integrate both with such low distortion that the focus region becomes hard to identify. We combine focus maps with partial schematization to display distortion of the context and to emphasize the focus region. Schematization visually conveys geographical accuracy, while not increasing map complexity. We extend the focusmap algorithm to incorporate geometric proximity relationships and show how to combine focus maps with schematization in order to cater to different use cases. @inproceedings{vanDijkEtAl2013,
abstract = {We present an algorithm for schematized focus maps. Focus maps integrate a high detailed, enlarged focus region continuously in a given base map. Recent methods integrate both with such low distortion that the focus region becomes hard to identify. We combine focus maps with partial schematization to display distortion of the context and to emphasize the focus region. Schematization visually conveys geographical accuracy, while not increasing map complexity. We extend the focusmap algorithm to incorporate geometric proximity relationships and show how to combine focus maps with schematization in order to cater to different use cases.},
author = {T. C. van Dijk and A. van Goethem and J.H. Haunert and W. Meulemans and B. Speckmann},
booktitle = {Proc. 21st ACM SIGSPATIAL International Conference on Advances in Geographic Information Systems (ACM SIGSPATIAL GIS '13)},
doi = {10.1145/2525314.2525452},
pages = {418421},
title = {Accentuating focus maps via partial schematization},
year = {2013}
}


T. C. van Dijk, and J.H. Haunert. A probabilistic model for road selection in mobile maps. In Proc. 12th International Symposium on Web and Wireless Geographical Information Systems (W2GIS'13), pages 214222. 2013.
abstract
doi
bibtex

 Mobile devices provide an interesting context for map drawing. This paper presents a novel roadselection algorithm based on PageRank, the algorithm famously used by Google to rank web pages by importance. Underlying the PageRank calculation is a probabilistic model of user behavior. We provide suitable generalizations of this model to road networks. Our implementation of the proposed algorithm handles a sizable map in approximately a tenth of a second on a desktop PC. Therefore, our methods should be feasible on modern mobile devices. @inproceedings{VanDijkHaunert2013,
abstract = {Mobile devices provide an interesting context for map drawing. This paper presents a novel roadselection algorithm based on PageRank, the algorithm famously used by Google to rank web pages by importance. Underlying the PageRank calculation is a probabilistic model of user behavior. We provide suitable generalizations of this model to road networks. Our implementation of the proposed algorithm handles a sizable map in approximately a tenth of a second on a desktop PC. Therefore, our methods should be feasible on modern mobile devices.},
author = {van Dijk, T. C. and Haunert, J.H.},
booktitle = {Proc. 12th International Symposium on Web and Wireless Geographical Information Systems (W2GIS'13)},
doi = {10.1007/9783642370878_16},
pages = {214222},
timestamp = {20130129T14:57:51.000+0100},
title = {A probabilistic model for road selection in mobile maps},
year = {2013}
}


T. C. van Dijk, K. Fleszar, J.H. Haunert, and J. Spoerhase. Road segment selection with strokes and stability. In Proc. 1st ACM SIGSPATIAL Workshop on MapInteraction. 2013.
abstract
doi
bibtex

 In order to visualize a road network without producing visual clutter, a subset of all road segments needs to be selected. Many algorithms for road segment selection are based on a relevance score for edges in a network (for example betweenness centrality) and proceed by taking a greedy selection based on these weights. This can give dissatisfactory results. In order to improve readability, we introduce a strokebased constraint and provide an efficient dynamic program that makes an optimal selection given this constraint. Next, we consider the computation of animated road selections from changing edge weights (for example a focus area that follows a moving user). Handling each time step of the animation individually can lead to distracting flickering effects. Here we introduce an optimization objective to achieve a more stable selection and provide a polynomialtime algorithm for solving it. While separately solvable in polynomial time, we show that the combination of the stroke constraints and stability optimization is NPhard. @inproceedings{vanDijkHaunert2013b,
abstract = {In order to visualize a road network without producing visual clutter, a subset of all road segments needs to be selected. Many algorithms for road segment selection are based on a relevance score for edges in a network (for example betweenness centrality) and proceed by taking a greedy selection based on these weights. This can give dissatisfactory results. In order to improve readability, we introduce a strokebased constraint and provide an efficient dynamic program that makes an optimal selection given this constraint. Next, we consider the computation of animated road selections from changing edge weights (for example a focus area that follows a moving user). Handling each time step of the animation individually can lead to distracting flickering effects. Here we introduce an optimization objective to achieve a more stable selection and provide a polynomialtime algorithm for solving it. While separately solvable in polynomial time, we show that the combination of the stroke constraints and stability optimization is NPhard.},
author = {van Dijk, T. C. and Fleszar, K. and Haunert, J.H. and Spoerhase, J.},
booktitle = {Proc. 1st ACM SIGSPATIAL Workshop on MapInteraction},
doi = {10.1145/2534931.2534936},
journal = {Unknown Journal},
title = {Road segment selection with strokes and stability},
year = {2013}
}


S. LochDehbi, Y. Dehbi, and L. Plümer. Stochastic reasoning for uav supported reconstruction of 3d building models. In volume XL1/W2 of ISPRS Annals of Photogrammetry, Remote Sensing and Spatial Information Sciences. Proc. UAVg Conference 2013, pages 257261. 2013.
abstract
doi
bibtex

 The acquisition of detailed information for buildings and their components becomes more and more important. However, an automatic reconstruction needs highresolution measurements. Such features can be derived from images or 3D laserscans that are e.g. taken by unmanned aerial vehicles (UAV). Since this data is not always available or not measurable at the first for example due to occlusions we developed a reasoning approach that is based on sparse observations. It benefits from an extensive prior knowledge of probability density distributions and functional dependencies and allows for the incorporation of further structural characteristics such as symmetries. Bayesian networks are used to determine posterior beliefs. Stochastic reasoning is complex since the problem is characterized by a mixture of discrete and continuous parameters that are in turn correlated by nonlinear constraints. To cope with this kind of complexity, the implemented reasoner combines statistical methods with constraint propagation. It generates a limited number of hypotheses in a modelbased topdown approach. It predicts substructures in building facades  such as windows  that can be used for specific UAV navigations for further measurements. @inproceedings{isprsarchivesXL1W22572013,
abstract = {The acquisition of detailed information for buildings and their components becomes more and more important. However, an automatic reconstruction needs highresolution measurements. Such features can be derived from images or 3D laserscans that are e.g. taken by unmanned aerial vehicles (UAV). Since this data is not always available or not measurable at the first for example due to occlusions we developed a reasoning approach that is based on sparse observations. It benefits from an extensive prior knowledge of probability density distributions and functional dependencies and allows for the incorporation of further structural characteristics such as symmetries. Bayesian networks are used to determine posterior beliefs. Stochastic reasoning is complex since the problem is characterized by a mixture of discrete and continuous parameters that are in turn correlated by nonlinear constraints. To cope with this kind of complexity, the implemented reasoner combines statistical methods with constraint propagation. It generates a limited number of hypotheses in a modelbased topdown approach. It predicts substructures in building facades  such as windows  that can be used for specific UAV navigations for further measurements.},
author = {LochDehbi, S. and Dehbi, Y. and Pl\"umer, L.},
booktitle = {Proc. UAVg Conference 2013},
doi = {10.5194/isprsarchivesXL1W22572013},
pages = {257261},
series = {ISPRS Annals of Photogrammetry, Remote Sensing and Spatial Information Sciences},
title = {Stochastic reasoning for UAV supported reconstruction of 3D building models},
url = {https://www.intarchphotogrammremotesensspatialinfsci.net/XL1W2/257/2013/},
volume = {XL1/W2},
year = {2013}
}


A. Gemsa, B. Niedermann, and M. Nöllenburg. Trajectorybased dynamic map labeling. In Proceedings of the 29th European Workshop on Computational Geometry (EuroCG'13). 2013.
bibtex

 @inproceedings{gnntbdml13,
author = {A. Gemsa and B. Niedermann and M. N{\"o}llenburg},
booktitle = {Proceedings of the 29th European Workshop on Computational Geometry (EuroCG'13)},
title = {{TrajectoryBased Dynamic Map Labeling}},
year = {2013}
}


A. Gemsa, B. Niedermann, and M. Nöllenburg. Trajectorybased dynamic map labeling. In volume 8283 of Lecture Notes in Computer Science. Proceedings of the 24th International Symposium on Algorithms and Computation (ISAAC'13), pages 413423. Springer, 2013. Full version available at http://arxiv.org/abs/1309.3963.
bibtex

 @inproceedings{gnntbdmlisaac13,
author = {A. Gemsa and B. Niedermann and M. N{\"o}llenburg},
booktitle = {Proceedings of the 24th International Symposium on Algorithms and Computation (ISAAC'13)},
file = {gnntbdmlisaac13.pdf:http\://i11www.ira.uka.de/extra/publications/gnntbdmlisaac13.pdf:PDF},
note = {Full version available at http://arxiv.org/abs/1309.3963.},
pages = {413423},
publisher = {Springer},
series = {Lecture Notes in Computer Science},
title = {{TrajectoryBased Dynamic Map Labeling}},
url = {http://dx.doi.org/10.1007/9783642450303_39},
volume = {8283},
year = {2013}
}


P. Kindermann, B. Niedermann, I. Rutter, M. Schaefer, A. Schulz, and A. Wolff. Twosided boundary labeling with adjacent sides. In Proceedings of the 29th European Workshop on Computational Geometry (EuroCG'13). 2013.
bibtex

 @inproceedings{knrsswtsbla13,
author = {P. Kindermann and B. Niedermann and I. Rutter and M. Schaefer and A. Schulz and A. Wolff},
booktitle = {Proceedings of the 29th European Workshop on Computational Geometry (EuroCG'13)},
title = {{TwoSided Boundary Labeling with Adjacent Sides}},
year = {2013}
}


P. Kindermann, B. Niedermann, I. Rutter, M. Schaefer, A. Schulz, and A. Wolff. Twosided boundary labeling with adjacent sides. In volume 8037 of Lecture Notes in Computer Science. Algorithms and Data Structures, 13th International Symposium (WADS'13), pages 463474. Springer, 2013.
bibtex

 @inproceedings{knrsstsbla13,
author = {P. Kindermann and B. Niedermann and I. Rutter and M. Schaefer and A. Schulz and A. Wolff},
booktitle = {Algorithms and Data Structures, 13th International Symposium (WADS'13)},
pages = {463474},
publisher = {Springer},
series = {Lecture Notes in Computer Science},
title = {{TwoSided Boundary Labeling with Adjacent Sides}},
volume = {8037},
year = {2013}
}


T. Biedl, T. Bläsius, B. Niedermann, M. Nöllenburg, R. Prutkin, and I. Rutter. Using ILP/SAT to determine pathwidth, visibility representations, and other gridbased graph drawings. In Stephen K. Wismath, and A. Wolff, editors, volume 8242 of Lecture Notes in Computer Science. Proceedings of the 21st International Symposium on Graph Drawing (GD'13), pages 460471. Springer, 2013. Full version available at http://arxiv.org/abs/1308.6778.
bibtex

 @inproceedings{bbnnpruilps13,
author = {T. Biedl and T. Bl{\"a}sius and B. Niedermann and M. N{\"o}llenburg and R. Prutkin and I. Rutter},
booktitle = {Proceedings of the 21st International Symposium on Graph Drawing (GD'13)},
editor = {Stephen K. Wismath and A. Wolff},
file = {bbnnpruilps13.pdf:http\://i11www.ira.uka.de/extra/publications/bbnnpruilps13.pdf:PDF},
note = {Full version available at http://arxiv.org/abs/1308.6778.},
pages = {460471},
publisher = {Springer},
series = {Lecture Notes in Computer Science},
title = {{Using {ILP/SAT} to determine pathwidth, visibility representations, and other gridbased graph drawings}},
url = {http://dx.doi.org/10.1007/9783319038414_40},
volume = {8242},
year = {2013}
}
