Filters








18,912 Hits in 2.6 sec

Map Schematization with Circular Arcs [chapter]

Thomas C. van Dijk, Arthur van Goethem, Jan-Henrik Haunert, Wouter Meulemans, Bettina Speckmann
2014 Lecture Notes in Computer Science  
We present an algorithm to compute schematic maps with circular arcs.  ...  Our algorithm iteratively replaces two consecutive arcs with a single arc to reduce the complexity of the output map and thus to increase its level of abstraction.  ...  Conclusion We presented an algorithm for circular-arc schematization of geographic maps. Our algorithm is able to schematize across junctions (vertices of degree three or higher).  ... 
doi:10.1007/978-3-319-11593-1_1 fatcat:u3hgd6wkpbgndc4iz4v64iyzza

Circular-Arc Cartograms [article]

Jan-Hinrich Kämper, Stephen G. Kobourov, Martin Nöllenburg
2012 arXiv   pre-print
We present a new circular-arc cartogram model in which countries are drawn as polygons with circular arcs instead of straight-line segments.  ...  Next we describe a heuristic method for constructing circular-arc cartograms, which uses a max-flow computation on the dual graph of the map, along with a computation of the straight skeleton of the underlying  ...  Fig. 7 : 7 Circular-arc cartograms produced by our method. The schematized octilinear input maps are drawn in gray and the resulting circular-arc cartograms in black.  ... 
arXiv:1112.4626v2 fatcat:4a4dvl466jfebosezcsphwxjwa

Exploring Curved Schematization

Arthur Van Goethem, Wouter Meulemans, Bettina Speckmann, Jo Wood
2014 2014 IEEE Pacific Visualization Symposium  
Our algorithm converts a simple polygon into a schematic crossing-free representation using circular arcs.  ...  ABSTRACT Hand-drawn schematized maps traditionally make extensive use of curves.  ...  geographic maps, schematized maps, and schematized representations.  ... 
doi:10.1109/pacificvis.2014.11 dblp:conf/apvis/GoethemMSW14 fatcat:ajktulcoizfe3pnxwlxl3qotgi

Circular-arc cartograms

Jan-Hinrich Kamper, Stephen G. Kobourov, Martin Nollenburg
2013 2013 IEEE Pacific Visualization Symposium (PacificVis)  
Newman [19] (d) Circular-arc cartogram generated by our method ABSTRACT We present a new circular-arc cartogram model in which countries are drawn as polygons with circular arcs instead of straight-line  ...  Given a political map and values associated with each country in the map, a cartogram is a distorted map in which the areas of the countries are proportional to the corresponding values.  ...  We thank Wouter Meulemans for providing us with schematized map instances.  ... 
doi:10.1109/pacificvis.2013.6596121 dblp:conf/apvis/KamperKN13 fatcat:w4yqe2kg5vdi7hd6ehrgd6xa5y

Exploring Curved Schematization of Territorial Outlines

Arthur van Goethem, Wouter Meulemans, Bettina Speckmann, Jo Wood
2015 IEEE Transactions on Visualization and Computer Graphics  
We present a new algorithm for areapreserving curved schematization of geographic outlines. Our algorithm converts a simple polygon into a schematic crossing-free representation using circular arcs.  ...  The method can be steered towards different degrees of "curviness": we can encourage or discourage the use of arcs with a large central angle via a single parameter.  ...  We present an algorithm for schematization with circular arcs. For an input consisting of n edges, our algorithm runs in O(n 2 ) time.  ... 
doi:10.1109/tvcg.2015.2401025 pmid:26357253 fatcat:pgpn42f5obhfjnt5vjnrz5sabi

Accentuating focus maps via partial schematization

Thomas van Dijk, Arthur van Goethem, Jan-Henrik Haunert, Wouter Meulemans, Bettina Speckmann
2013 Proceedings of the 21st ACM SIGSPATIAL International Conference on Advances in Geographic Information Systems - SIGSPATIAL'13  
We combine focus maps with partial schematization to display distortion of the context and to emphasize the focus region.  ...  We extend the focus-map algorithm to incorporate geometric proximity relationships and show how to combine focus maps with schematization in order to cater to different use cases.  ...  Beyond a reduction of the level of detail, however, schematization enforces a certain design scheme (we use circular arcs in this paper).  ... 
doi:10.1145/2525314.2525452 dblp:conf/gis/DijkGHMS13 fatcat:tmzsngjm4valldttd44vyak46m

Topologically Safe Curved Schematisation

Arthur van Goethem, Wouter Meulemans, Andreas Reimer, Herman Haverkort, Bettina Speckmann
2013 The Cartographic Journal  
We illustrate our framework with Bézier curves and circular arcs.  ...  Traditionally schematized maps make extensive use of curves. However, automated methods for schematization are mostly restricted to straight lines.  ...  Result with 30 Bézier curves (middle) and with 30 circular arcs (right). Figure 14 : 14 (Top) Downsized map of Antarctica (Militärgeographisches Amt (ed.) 1982).  ... 
doi:10.1179/1743277413y.0000000066 fatcat:f27bkxi6yvcsfberwuoyoyzsny

Meshing molecular surfaces based on analytical implicit representation

Chaoyu Quan, Benjamin Stamm
2017 Journal of Molecular Graphics and Modelling  
The MSMS algorithm can also provide a triangulation of the SES with a user-specified density of vertices.  ...  This surface model has been applied to a very large variety of problems and has also been used to compute solvation energies with continuum solvation models [1, 3, 7] .  ...  To represent each circular arc, we record the starting and ending point, its center, radius, radian and the pair of SAS-spheres with the following data structure: Circular SAS Arc • (i 1 , i 2 ): index  ... 
doi:10.1016/j.jmgm.2016.11.008 pmid:27939932 fatcat:crpiqo5trje3thoxzqhu3ebbd4

Schwarz–Christoffel mappings to unbounded multiply connected polygonal regions

DARREN CROWDY
2007 Mathematical proceedings of the Cambridge Philosophical Society (Print)  
The formula for the derivative of the mapping function is shown to contain a product of powers of Schottky-Klein prime functions associated with the circular preimage domain.  ...  First, it is compared with a known formula in the doubly connected case.  ...  The author acknowledges useful discussions with Jonathan Marshall and thanks Alan Elcrat for sending him a preprint of [9] .  ... 
doi:10.1017/s0305004106009832 fatcat:r6kpbwkaina3bl3b4rdnlec6ya

Complementary Sequence-Mediated Exon Circularization

Xiao-Ou Zhang, Hai-Bin Wang, Yang Zhang, Xuhua Lu, Ling-Ling Chen, Li Yang
2014 Cell  
By using genome-wide approaches and circular RNA recapitulation, we demonstrate that exon circularization is dependent on flanking intronic complementary sequences.  ...  Importantly, alternative formation of inverted repeated Alu pairs and the competition between them can lead to alternative circularization, resulting in multiple circular RNA transcripts produced from  ...  NB was performed with probes indicated in left panels. NB bands for circular RNAs are indicated with schematic circles (in blue).  ... 
doi:10.1016/j.cell.2014.09.001 pmid:25242744 fatcat:nfveunxxkjf2lgmtihhp2l2wka

Conformal mappings to a doubly connected polycircular arc domain

D.G. Crowdy, A.S. Fokas
2007 Proceedings of the Royal Society A  
As an analytical check of the formula, a special exact solution for a doubly connected polycircular arc mapping is derived and compared with that obtained from the more general construction.  ...  The construction of an analogous formula for the case of a polycircular arc domain, i.e. for a doubly connected domain whose boundaries are a union of circular arc segments, has remained an important open  ...  Similarly, P (1) is a union of n 1 circular arc segments with associated equations z KD ð1Þ k 2 Z Q ð1Þ k 2 ; k Z 1; .; n 1 : ð2:2Þ The conformal mapping problem is to find the functional form of a conformal  ... 
doi:10.1098/rspa.2007.1847 fatcat:pient6gazng6vhwqgkgrpeywci

Observation of Three-dimensional Photonic Dirac points and Spin-polarized Surface Arcs [article]

Qinghua Guo, Oubo You, Biao Yang, James B. Sellman, Edward Blythe, Hongchao Liu, Yuanjiang Xiang, Jensen Li, Dianyuan Fan, Jing Chen, C. T. Chan, Shuang Zhang
2018 arXiv   pre-print
It shares multiple exotic topological features with other topological materials, such as Fermi arcs and chiral anomaly with Weyl semimetals30, spin-dependent surface states with topological insulators29  ...  Spin-polarized surface arcs (counterparts of Fermi arcs in electronic systems) are demonstrated, which paves the way towards spin-multiplexed topological surface wave propagation.  ...  Further effective media analysis 40 shows that the two Fermi arcs exhibit left/right circular polarization (L/RCP) with the plane of the polarization parallels to the Fermi arcs.  ... 
arXiv:1810.02354v1 fatcat:3hka3fnm5nd7nlywo2rabkdz4a

The Unusual Projection for One of John Dee's Maps of 1580

David I Bower
2012 The Cartographic Journal  
A brief description is given of the cartographic activity of John Dee, which involved the production of at least three manuscript maps in the years 1580-1583 in connection with exploration and imperial  ...  The form of an idealised version of the unusual projection used in one of the maps dated 1580 is discussed and it is shown how it may be considered to be related to projections developed between antiquity  ...  The parallels are circular arcs equally spaced and centred at the pole.  ... 
doi:10.1179/1743277411y.0000000015 fatcat:pid72pd7jfds7jp5woq336wyqy

Planar Lombardi Drawings for Subcubic Graphs [chapter]

David Eppstein
2013 Lecture Notes in Computer Science  
We prove that every planar graph with maximum degree three has a planar drawing in which the edges are drawn as circular arcs that meet at equal angles around every vertex.  ...  By Fáry's theorem, every planar graph can be drawn planarly with straight line segments for its edges, and therefore it can also be drawn with circular arcs.  ...  Because G 18 is 4-regular, it has a Lombardi drawing with a circular layout, with the arcs representing its edges forming 45 • angles to the circle on which the vertices are drawn [10] .  ... 
doi:10.1007/978-3-642-36763-2_12 fatcat:gudlcurgjraz3ntyhnbm4bdoqi

Planar Lombardi Drawings for Subcubic Graphs [article]

David Eppstein
2012 arXiv   pre-print
We prove that every planar graph with maximum degree three has a planar drawing in which the edges are drawn as circular arcs that meet at equal angles around every vertex.  ...  By Fáry's theorem, every planar graph can be drawn planarly with straight line segments for its edges, and therefore it can also be drawn with circular arcs.  ...  Because G 18 is 4-regular, it has a Lombardi drawing with a circular layout, with the arcs representing its edges forming 45 • angles to the circle on which the vertices are drawn [10] .  ... 
arXiv:1206.6142v1 fatcat:uv6y74c75rgjvlrex27fwgeyeq
« Previous Showing results 1 — 15 out of 18,912 results