Filters








7,371 Hits in 3.7 sec

On Contact Graphs with Cubes and Proportional Boxes [chapter]

M. Jawaherul Alam, Michael Kaufmann, Stephen G. Kobourov
2016 Lecture Notes in Computer Science  
We study two variants of the problem of contact representation of planar graphs with axis-aligned boxes.  ...  We show how to construct such representations representation for some classes of planar graphs.  ...  If G is planar, then it is called a planar 3-tree. A plane 3-tree is a planar 3-tree along with a fixed planar embedding.  ... 
doi:10.1007/978-3-662-49192-8_9 fatcat:ccqlcjhr4bajbf6swcllnwnfzu

Fine-Grained Location-Free Planarization in Wireless Sensor Networks

Dezun Dong, Xiangke Liao, Yunhao Liu, Xiang-Yang Li, Zhengbin Pang
2013 IEEE Transactions on Mobile Computing  
The planar topologies constructed by current location-free methods often have large stretch factors.  ...  The simulation results show that our method produces high-quality planar graphs with a small stretch factor in practical large-scale networks.  ...  ACKNOWLEDGMENTS The authors are grateful for a variety of valuable comments from the anonymous reviewers. Dezun Dong  ... 
doi:10.1109/tmc.2012.57 fatcat:wmtevvq7k5fvdd4n7nnfkonmai

Fine-grained location-free planarization in wireless sensor networks

Dezun Dong, Yunhao Liu, Xiangke Liao, Xiang-Yang Li
2011 2011 Proceedings IEEE INFOCOM  
The planar topologies constructed by current location-free methods often have large stretch factors.  ...  The simulation results show that our method produces high-quality planar graphs with a small stretch factor in practical large-scale networks.  ...  ACKNOWLEDGMENTS The authors are grateful for a variety of valuable comments from the anonymous reviewers. Dezun Dong  ... 
doi:10.1109/infcom.2011.5934878 dblp:conf/infocom/DongLLL11 fatcat:ghdcuffg5bcnxaeieqwtsz37xa

Intersection graphs of L-shapes and segments in the plane

Stefan Felsner, Kolja Knauer, George B. Mertzios, Torsten Ueckerdt
2016 Discrete Applied Mathematics  
any format or medium without the formal permission of the copyright holders.  ...  provided that: • a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in  ...  Here we give an easy proof for a non-trivial subclass of planar graphs, namely planar 3-trees. A 3-tree is an edge-maximal graph of treewidth 3.  ... 
doi:10.1016/j.dam.2016.01.028 fatcat:t7z7jvn6anfrlor4ar6v5lfese

Intersection Graphs of L-Shapes and Segments in the Plane [chapter]

Stefan Felsner, Kolja Knauer, George B. Mertzios, Torsten Ueckerdt
2014 Lecture Notes in Computer Science  
any format or medium without the formal permission of the copyright holders.  ...  provided that: • a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in  ...  Here we give an easy proof for a non-trivial subclass of planar graphs, namely planar 3-trees. A 3-tree is an edge-maximal graph of treewidth 3.  ... 
doi:10.1007/978-3-662-44465-8_26 fatcat:7vaqzk7xyjbl3aiqpcyb6guhuu

1-String B_1-VPG Representations of Planar Partial 3-Trees and Some Subclasses [article]

Therese Biedl, Martin Derka
2015 arXiv   pre-print
We also that some subclasses of planar partial 3-trees have L-representations, i.e., a B_1-VPG representation where every curve has the shape of an L.  ...  Planar partial 3-trees are subgraphs of those planar graphs obtained by repeatedly inserting a vertex of degree 3 into a face.  ...  However, for some subclasses of planar partial 3-trees, we can show that fewer shapes suffice.  ... 
arXiv:1506.07246v1 fatcat:63yszsx7cffvbdovftwgb43yey

Intersection Graphs of L-Shapes and Segments in the Plane [article]

Stefan Felsner, Kolja Knauer, George B. Mertzios, Torsten Ueckerdt
2016 arXiv   pre-print
We show that all planar 3-trees, all line graphs of planar graphs, and all full subdivisions of planar graphs are {L}-graphs.  ...  An L-shape is the union of a horizontal and a vertical segment with a common endpoint. These come in four rotations: L, Γ, LE and .  ...  Is there a parameter of SEG-graphs or SEGrepresentations ensuring few bends in their VPG-representations? It is known that the number of slopes in the SEG-representation is not the right answer [6] .  ... 
arXiv:1405.1476v2 fatcat:ekp6twulfrcmpa56wbu2bn6aqe

1-string B1-VPG-representations of planar partial 3-trees and some subclasses

Therese C. Biedl, Martin Derka
2015 Canadian Conference on Computational Geometry  
We also show that some subclasses of planar partial 3-trees have {L}representations, i.e., a B 1 -VPG representation where every curve has the shape of an L.  ...  Planar partial 3-trees are subgraphs of those planar graphs obtained by repeatedly inserting a vertex of degree 3 into a face.  ...  However, for some subclasses of planar partial 3-trees, we can show that fewer shapes suffice.  ... 
dblp:conf/cccg/BiedlD15 fatcat:egiwopn7vvh6hc7p7e5ye5qsoy

Advances in the theory and practice of graph drawing

Roberto Tamassia
1999 Theoretical Computer Science  
Foremost among the visual representations used are drawings of graphs and ordered sets. In this talk, we survey recent advances in the theory and practice of graph drawing.  ...  The visualization of conceptual structures is a key component of support tools for complex applications in science and engineering.  ...  This would provide graphical user interfaces with the flexibility of fitting drawings in arbitrarily shaped windows.  ... 
doi:10.1016/s0304-3975(98)00272-2 fatcat:2ctscsnpxrg6zbu2cmcgo3raoi

Planar spanners and approximate shortest path queries among obstacles in the plane [chapter]

Srinivasa Arikati, Danny Z. Chen, L. Paul Chew, Gautam Das, Michiel Smid, Christos D. Zaroliagis
1996 Lecture Notes in Computer Science  
In this paper, we give a family of algorithms for the above problem that achieve an interesting trade-off between the stretch factor, the query time and the preprocessing bounds.  ...  The length of this path should be within a small constant factor c of the length of the shortest possible obstacle-avoiding s-t path measured in the Lv-metric.  ...  This subdivision is a planar graph where each face is a connected region called a cell. The shapes of the cells have special significance, and are best described through the concept of boxes.  ... 
doi:10.1007/3-540-61680-2_79 fatcat:b74j7fgj6bbxtenmcxrzfqizeq

A node-capacitated okamura-seymour theorem

James R. Lee, Manor Mendel, Mohammad Moharrami
2013 Proceedings of the 45th annual ACM symposium on Symposium on theory of computing - STOC '13  
The classical Okamura-Seymour theorem states that for an edge-capacitated, multi-commodity flow instance in which all terminals lie on a single face of a planar graph, there exists a feasible concurrent  ...  This answers an open question of Chekuri and Kawarabayashi. More generally, we show that this holds in the setting of multi-commodity polymatroid networks introduced by Chekuri, et. al.  ...  Acknowledgements We are grateful to Chandra Chekuri and Bruce Shepherd for bringing the node-capacitated problem to our attention and for their encouragement during the course of the project.  ... 
doi:10.1145/2488608.2488671 dblp:conf/stoc/LeeMM13 fatcat:67hollvphvew7pgmeh7fvnbace

A node-capacitated Okamura–Seymour theorem

James R. Lee, Manor Mendel, Mohammad Moharrami
2014 Mathematical programming  
The classical Okamura-Seymour theorem states that for an edge-capacitated, multi-commodity flow instance in which all terminals lie on a single face of a planar graph, there exists a feasible concurrent  ...  This answers an open question of Chekuri and Kawarabayashi. More generally, we show that this holds in the setting of multi-commodity polymatroid networks introduced by Chekuri, et. al.  ...  Acknowledgements We are grateful to Chandra Chekuri and Bruce Shepherd for bringing the node-capacitated problem to our attention and for their encouragement during the course of the project.  ... 
doi:10.1007/s10107-014-0810-0 fatcat:qrl6qndvkve75hkvl36gyc765e

SLICE: Enabling Greedy Routing in High Genus 3-D WSNs With General Topologies

Chen Wang, Hongbo Jiang, Tianlong Yu, John C. S. Lui
2016 IEEE/ACM Transactions on Networking  
, resulting in a lower routing stretch. 2) This is the first work, to the best of our knowledge, that enables greedy routing in high genus 3-D WSNs with general topologies.  ...  Then, to achieve a lower distance distortion, we purposely propose a variation of the Ricci flow algorithm, by which this open surface is flattened not to a planar annulus, but to a planar convex polygon  ...  Since the deformation process of Ricci flow is conformal (angle-preserving) [28] , [29] , the value of the distance stretch is closely related to the shape changes from to : the more shape changes, the  ... 
doi:10.1109/tnet.2015.2464312 fatcat:iwefmc4mtzezhke47qlwnxwbde

Page 4567 of Mathematical Reviews Vol. , Issue 96h [page]

1996 Mathematical Reviews  
{For the entire collection see MR 96g:05003.} 96h:05179 05C80 05C05 Maier, Robert S. (1-AZ; Tucson, AZ) The shape of stretched planar trees.  ...  Summary: “We study the asymptotics of a ‘stretched’ model of un- labeled rooted planar trees, in which trees are not taken equiprob- able but are weighted exponentially, according to their height.  ... 

Rendering parametric surfaces in pen and ink

Georges Winkenbach, David H. Salesin
1996 Proceedings of the 23rd annual conference on Computer graphics and interactive techniques - SIGGRAPH '96  
In particular, we introduce the idea of "controlled-density hatching" for conveying tone, texture, and shape.  ...  The fine control over tone this method provides allows the use of traditional texture mapping techniques for specifying the tone of pen-and-ink illustrations.  ...  Acknowledgments We would like to thank Jorge Stolfi for many useful discussions during the early phase of this project.  ... 
doi:10.1145/237170.237287 dblp:conf/siggraph/WinkenbachS96 fatcat:eo64y737hff53ho5uezmthbkqu
« Previous Showing results 1 — 15 out of 7,371 results