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Displaying 1-15 out of 15 total
Flow Map Layout via Spiral Trees
Found in: IEEE Transactions on Visualization and Computer Graphics
By Kevin Buchin,Bettina Speckmann,Kevin Verbeek
Issue Date:December 2011
pp. 2536-2544
Flow maps are thematic maps that visualize the movement of objects, such as people or goods, between geographic regions. One or more sources are connected to several targets by lines whose thickness corresponds to the amount of flow between a source and a ...
 
Exploring Curved Schematization
Found in: 2014 IEEE Pacific Visualization Symposium (PacificVis)
By Arthur Van Goethem,Wouter Meulemans,Bettina Speckmann,Jo Wood
Issue Date:March 2014
pp. 1-8
Hand-drawn schematized maps traditionally make extensive use of curves. However, there are few automated approaches for curved schematization most previous work focuses on straight lines. We present a new algorithm for area-preserving curved schematization...
 
Necklace Maps
Found in: IEEE Transactions on Visualization and Computer Graphics
By Bettina Speckmann, Kevin Verbeek
Issue Date:November 2010
pp. 881-889
Statistical data associated with geographic regions is nowadays globally available in large amounts and hence automated methods to visually display these data are in high demand. There are several well-established thematic map types for quantitative data o...
 
Delineating imprecise regions via shortest-path graphs
Found in: Proceedings of the 19th ACM SIGSPATIAL International Conference on Advances in Geographic Information Systems (GIS '11)
By Bettina Speckmann, Mark de Berg, Wouter Meulemans
Issue Date:November 2011
pp. 271-280
An imprecise region, also called a vernacular region, is a region without a precise or administrative boundary. We present a new method to delineate imprecise regions from a set of points that are likely to lie inside the region. We use shortest-path graph...
     
A new method for subdivision simplification with applications to urban-area generalization
Found in: Proceedings of the 19th ACM SIGSPATIAL International Conference on Advances in Geographic Information Systems (GIS '11)
By Bettina Speckmann, Kevin Buchin, Wouter Meulemans
Issue Date:November 2011
pp. 261-270
We introduce a local operation for polygons and subdivisions called an edge-move. Edge-moves do not change the edge orientations present in the input and are thus suitable for iterative simplification or even schematization. Based on edge-moves we present ...
     
A splitting line model for directional relations
Found in: Proceedings of the 19th ACM SIGSPATIAL International Conference on Advances in Geographic Information Systems (GIS '11)
By Bettina Speckmann, Bogdan Vasilescu, Frank Staals, Kevin Buchin, Vincent Kusters
Issue Date:November 2011
pp. 142-151
Directional relations are fundamental to spatial data queries, analysis and reasoning. Consequently there has been a significant amount of effort to determine directional relations between two regions. However, many existing methods do not perform well whe...
     
Kinetic convex hulls and delaunay triangulations in the black-box model
Found in: Proceedings of the 27th annual ACM symposium on Computational geometry (SoCG '11)
By Bettina Speckmann, Marcel Roeloffzen, Mark de Berg
Issue Date:June 2011
pp. 244-253
Over the past decade, the kinetic-data-structures framework has become the standard in computational geometry for dealing with moving objects. A fundamental assumption underlying the framework is that the motions of the objects are known in advance. This a...
     
Area-universal rectangular layouts
Found in: Proceedings of the 25th annual symposium on Computational geometry (SCG '09)
By Bettina Speckmann, David Eppstein, Elena Mumford, Kevin Verbeek
Issue Date:June 2009
pp. 159-162
A rectangular layout is a partition of a rectangle into a finite set of interior-disjoint rectangles. They are used as rectangular cartograms in cartography, as floorplans in building architecture and VLSI design, and as graph drawings. Often areas are ass...
     
Rectangular cartograms: the game
Found in: Proceedings of the 25th annual symposium on Computational geometry (SCG '09)
By Bettina Speckmann, Fred van Nijnatten, Kevin Verbeek, Mark de Berg
Issue Date:June 2009
pp. 159-162
We demonstrate how the scale axis transform can be used to compute a parameterized family of shape skeletons. The skeletons gradually represent only the most important features of a shape, in a scale-adaptive manner. Here a shape O is any bounded open subs...
     
Kinetic KD-trees and longest-side KD-trees
Found in: Proceedings of the twenty-third annual symposium on Computational geometry (SCG '07)
By Bettina Speckmann, Mark de Berg, Mohammad Ali Abam
Issue Date:June 2007
pp. 364-372
The dynamic convex hull problem was recently solved in O(lg n) time per operation, and this result is best possible in models of computation with bounded branching (e.g., algebraic computation trees). From a data structures point of view, however, such mod...
     
Rectangular cartograms: construction & animation
Found in: Proceedings of the twenty-first annual symposium on Computational geometry (SCG '05)
By Bettina Speckmann, Marc van Kreveld, Sander Florisson
Issue Date:June 2005
pp. 372-373
In this video, we describe our experiences in implementing an algo-rithm to compute time-varying contour trees and highlight the chal-lenges in applying this algorithm to real-world scientific datasets. For ease of illustration we restrict our explanations...
     
Efficient detection of motion patterns in spatio-temporal data sets
Found in: Proceedings of the 12th annual ACM international workshop on Geographic information systems (GIS '04)
By Bettina Speckmann, Joachim Gudmundsson, Marc van Kreveld
Issue Date:November 2004
pp. 250-257
Moving point object data can be analyzed through the discovery of patterns. We consider the computational efficiency of detecting four such spatio-temporal patterns, namely flock, leadership, convergence, and encounter, as defined by Laube et al., 2004. Th...
     
Kinetic maintenance of context-sensitive hierarchical representations for disjoint simple polygons
Found in: Proceedings of the eighteenth annual symposium on Computational geometry (SCG '02)
By Bettina Speckmann, David Kirkpatrick
Issue Date:June 2002
pp. 179-188
We describe how to construct and kinetically maintain a tessellation of the free space between a collection of k disjoint simple polygonal objects with a total of N vertices, R of which are reflex. Our linear size tessellation consists of pseudo-triangles ...
     
Kinetic collision detection for simple polygons
Found in: Proceedings of the sixteenth annual symposium on Computational geometry (SCG '00)
By Bettina Speckmann, David Kirkpatrick, Jack Snoeyink
Issue Date:June 2000
pp. 322-330
An interactive visualization of weighted three-dimensional α-hulls is presented for static and dynamic spheres. The α-hull is analytically computed and represented by a triangulated mesh. The entire surface is computed and displayed in real-time ...
     
Efficient algorithms for maximum regression depth
Found in: Proceedings of the fifteenth annual symposium on Computational geometry (SCG '99)
By Bettina Speckmann, Jack Snoeyink, Joseph S. B. Mitchell, Marc van Kreveld, Micha Sharir, Peter Rousseeuw
Issue Date:June 1999
pp. 31-40
An interactive visualization of weighted three-dimensional α-hulls is presented for static and dynamic spheres. The α-hull is analytically computed and represented by a triangulated mesh. The entire surface is computed and displayed in real-time ...
     
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