Results 221 to 230 of about 364,146 (257)
Some of the next articles are maybe not open access.
Bézier representation of conics of contact in the projective plane
Computer Aided Geometric Design, 1994The authors consider conics which contact a plane curve in a point of second order (same tangent and curvature). The authors' main idea is to treat conics and more generally rational curves as elements of a suitable projective space. They use only tools of projective differential geometry for the investigations of the geometric properties of rational ...
Gerhard Geise, Th. Nestler
exaly +2 more sources
Representations by Contact and Intersection of Segments
Algorithmica, 2007A necessary and sufficient condition is given for a connected bipartite graph to be the incidence graph of a contact family of segments and points. We deduce that any four-connected three-colorable plane graph is the contact graph of a family of segments and that any four-colored planar graph without an induced C4 using four colors is the intersection ...
Hubert de Fraysseix +1 more
openaire +2 more sources
Contact representations of planar graphs with cubes
Proceedings of the twenty-seventh annual symposium on Computational geometry, 2011We prove that every planar graph has a representation using axis-parallel cubes in three dimensions in such a way that there is a cube corresponding to each vertex of the planar graph and two cubes have a non-empty intersection if and only if their corresponding vertices are adjacent.
Stefan Felsner, Mathew C. Francis
openaire +1 more source
3D proportional contact representations of graphs
IISA 2014, The 5th International Conference on Information, Intelligence, Systems and Applications, 2014In 3D contact representations, the vertices of a graph are represented by 3D polyhedra and the edges are realized by non-zero-area common boundaries between corresponding polyhedra. While contact representations with cuboids have been studied in the literature, we consider a novel generalization of the problem in which vertices are represented by axis ...
Md. Jawaherul Alam +4 more
openaire +1 more source
Equiangular Polygon Contact Representations
2018Planar graphs are known to have contact representations of various types. The most prominent example is Koebe’s ‘kissing coins theorem’. Its rediscovery by Thurston lead to effective versions of the Riemann Mapping Theorem and motivated Schramm’s Monster Packing Theorem.
Stefan Felsner +2 more
openaire +1 more source
On Contact Representations of Directed Planar Graphs
2018Prior work on contact representations of planar graphs deals with undirected graphs only. We introduce a notion of point-side contact representations for directed planar graphs. We show every outerplanar digraph of out-degree at most three to enjoy a point-side triangle contact representation.
Chun-Hsiang Chan, Hsu-Chun Yen
openaire +1 more source
Homothetic Triangle Contact Representations
2017We prove that every 4-connected planar triangulation admits a contact representation by homothetic triangles.
openaire +1 more source
Contact Representations of Planar Graphs: Extending a Partial Representation is Hard
2014Planar graphs are known to have geometric representations of various types, e.g. as contacts of disks, triangles or - in the bipartite case - vertical and horizontal segments. It is known that such representations can be drawn in linear time, we here wonder whether it is as easy to decide whether a partial representation can be completed to a ...
Steven Chaplick +4 more
openaire +1 more source
On the representation of contact states between curved objects
IEEE International Conference on Robotics and Automation, 2004. Proceedings. ICRA '04. 2004, 2004Information of high-level, topological contact states is useful and even necessary for a wide range of applications, including many robotic applications. A contact state between two polyhedral objects can be effectively represented as a contact formation in terms of a set of principal contacts between faces, edges, and vertices of the two objects ...
Qi Luo +2 more
openaire +1 more source
Contact states: representation and recognizability in the presence of uncertainties
Proceedings. 1998 IEEE/RSJ International Conference on Intelligent Robots and Systems. Innovations in Theory, Practice and Applications (Cat. No.98CH36190), 2002Recognition of contact states is often necessary or preferred in planning and executing contact-based assembly motions in the presence of uncertainties. However, due to inevitable uncertainties, not all contact states can be identified at all contact configurations.
Jing Xiao 0001, Lianzhong Liu
openaire +1 more source