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Art Gallery Problem
The art gallery problem or museum problem is a well-studied visibility problem in computational geometry. It originates from the following real-world problem: In the geometric version of the problem, the layout of the art gallery is represented by a simple polygon and each guard is represented by a point in the polygon. A set S of points is said to guard a polygon if, for every point p in the polygon, there is some q\in S such that the line segment between p and q does not leave the polygon. The art gallery problem can be applied in several domains such as in robotics, when artificial intelligences (AI) need to execute movements depending on their surroundings. Other domains, where this problem is applied, are in image editing, lighting problems of a stage or installation of infrastructures for the warning of natural disasters. Two dimensions There are numerous variations of the original problem that are also referred to as the art gallery problem. In some versions guards ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Visibility Problem
In geometry, visibility is a mathematical abstraction of the real-life notion of visibility. Given a set of obstacles in the Euclidean space, two points in the space are said to be visible to each other, if the line segment that joins them does not intersect any obstacles. (In the Earth's atmosphere light follows a slightly curved path that is not perfectly predictable, complicating the calculation of actual visibility.) Computation of visibility is among the basic problems in computational geometry and has applications in computer graphics, motion planning, and other areas. Concepts and problems * Point visibility * Edge visibilityE. Roth, G. Panin and A. Knoll,Sampling feature points for contour tracking with graphics hardware, "In International Workshop on Vision, Modeling and Visualization (VMV)", Konstanz, Germany, October 2008. * Visibility polygon * Weak visibility *Art gallery problem or museum problem *Visibility graph ** Visibility graph of vertical line segments * Wat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triangulation 3-coloring
In trigonometry and geometry, triangulation is the process of determining the location of a point by forming triangles to the point from known points. Applications In surveying Specifically in surveying, triangulation involves only angle measurements at known points, rather than measuring distances to the point directly as in trilateration; the use of both angles and distance measurements is referred to as triangulateration. In computer vision Computer stereo vision and optical 3D measuring systems use this principle to determine the spatial dimensions and the geometry of an item. Basically, the configuration consists of two sensors observing the item. One of the sensors is typically a digital camera device, and the other one can also be a camera or a light projector. The projection centers of the sensors and the considered point on the object's surface define a (spatial) triangle. Within this triangle, the distance between the sensors is the base ''b'' and must be known. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Godfried Toussaint
Godfried Theodore Patrick Toussaint (1944 – July 2019) was a Canadian computer scientist, a professor of computer science, and the head of the Computer Science Program at New York University Abu Dhabi (NYUAD) in Abu Dhabi, United Arab Emirates. He is considered to be the father of computational geometry in Canada. He did research on various aspects of computational geometry, discrete geometry, and their applications: pattern recognition (k-nearest neighbor algorithm, cluster analysis), motion planning, visualization (computer graphics), knot theory (stuck unknot problem), linkage (mechanical) reconfiguration, the art gallery problem, polygon triangulation, the largest empty circle problem, unimodality (unimodal function), and others. Other interests included meander (art), compass and straightedge constructions, instance-based learning, music information retrieval, and computational music theory. He was a co-founder of the Annual ACM Symposium on Computational Geometry, and the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jörg-Rüdiger Sack
Jörg-Rüdiger Wolfgang Sack (born in Duisburg, Germany) is a professor of computer science at Carleton University, where he holds the SUN–NSERC chair in Applied Parallel Computing.SUN–NSERC Chair in Applied Parallel Computing Carleton University. Sack received a master's degree from the in 1979Sack's web site at Carleton , retrieved 2009-11-20. and a Ph.D. in 1984 from |
Anna Lubiw
Anna Lubiw is a computer scientist known for her work in computational geometry and graph theory. She is currently a professor at the University of Waterloo. Education Lubiw received her Ph.D from the University of Toronto in 1986 under the joint supervision of Rudolf Mathon and Stephen Cook. Research At Waterloo, Lubiw's students have included both Erik Demaine and his father Martin Demaine, with whom she published the first proof of the fold-and-cut theorem in mathematical origami. In graph drawing, Hutton and Lubiw found a polynomial time algorithm for upward planar drawing of graphs with a single source vertex. Other contributions of Lubiw include proving the NP-completeness of finding permutation patterns, and of finding derangements in permutation groups. Awards Lubiw was named an ACM Distinguished Member in 2009. Personal life As well her academic work, Lubiw is an amateur violinist, and chairs the volunteer council in charge of the University of Waterloo orchest ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Daniel Kleitman
Daniel J. Kleitman (born October 4, 1934)article availableon Douglas West's web page, University of Illinois at Urbana–Champaign)."Kleitman, Daniel J.," in: ''Who's Who in Frontier Science and Technology'', 1, 1984, p. 396. is an American mathematician and professor of applied mathematics at MIT. His research interests include combinatorics, graph theory, genomics, and operations research. Biography Kleitman was born in 1934 in Brooklyn, New York, the younger of Bertha and Milton Kleitman's two sons. His father was a lawyer who after WWII became a commodities trader and investor. In 1942 the family moved to Morristown, New Jersey,. and he graduated from Morristown High School in 1950. Kleitman then attended Cornell University, from which he graduated in 1954, and received his PhD in Physics from Harvard University in 1958 under Nobel Laureates Julian Schwinger and Roy Glauber. He is the "k" in G. W. Peck, a pseudonym for a group of six mathematicians that includes Kleitman. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maria Klawe
Maria Margaret Klawe ( ; born 1951) is a computer scientist and the fifth president of Harvey Mudd College (since July 1, 2006). Born in Toronto in 1951, she became a naturalized U.S. citizen in 2009. She was previously Dean of the School of Engineering and Applied Science at Princeton University. She is known for her advocacy for women in STEM fields. Biography Klawe was born in Toronto, Ontario. She lived in Scotland from ages 4 to 12, and then returned to Canada, living with her family in Edmonton, Alberta.. Klawe studied at the University of Alberta, dropped out to travel the world, and returned to earn her B.Sc. in 1973. She stayed at Alberta for her graduate studies, and in 1977 she earned her Ph.D. there in mathematics. She joined the mathematics faculty at Oakland University as an assistant professor in 1977 but only stayed for a year. She started a second Ph.D., in computer science, at the University of Toronto, but was offered a faculty position there before completing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orthogonal Polygons
A rectilinear polygon is a polygon all of whose sides meet at right angles. Thus the interior angle at each vertex is either 90° or 270°. Rectilinear polygons are a special case of isothetic polygons. In many cases another definition is preferable: a rectilinear polygon is a polygon with sides parallel to the axes of Cartesian coordinates. The distinction becomes crucial when spoken about sets of polygons: the latter definition would imply that sides of all polygons in the set are aligned with the same coordinate axes. Within the framework of the second definition it is natural to speak of horizontal edges and vertical edges of a rectilinear polygon. Rectilinear polygons are also known as orthogonal polygons. Other terms in use are iso-oriented, axis-aligned, and axis-oriented polygons. These adjectives are less confusing when the polygons of this type are rectangles, and the term axis-aligned rectangle is preferred, although orthogonal rectangle and rectilinear rectangle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mathematical Induction
Mathematical induction is a method for proving that a statement ''P''(''n'') is true for every natural number ''n'', that is, that the infinitely many cases ''P''(0), ''P''(1), ''P''(2), ''P''(3), ... all hold. Informal metaphors help to explain this technique, such as falling dominoes or climbing a ladder: A proof by induction consists of two cases. The first, the base case, proves the statement for ''n'' = 0 without assuming any knowledge of other cases. The second case, the induction step, proves that ''if'' the statement holds for any given case ''n'' = ''k'', ''then'' it must also hold for the next case ''n'' = ''k'' + 1. These two steps establish that the statement holds for every natural number ''n''. The base case does not necessarily begin with ''n'' = 0, but often with ''n'' = 1, and possibly with any fixed natural number ''n'' = ''N'', establishing the truth of the statement for all natu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tree (graph Theory)
In graph theory In mathematics, graph theory is the study of ''graphs'', which are mathematical structures used to model pairwise relations between objects. A graph in this context is made up of '' vertices'' (also called ''nodes'' or ''points'') which are conne ..., a tree is an undirected graph in which any two Vertex (graph theory), vertices are connected by ''exactly one'' Path (graph theory), path, or equivalently a Connected graph, connected Cycle (graph theory), acyclic undirected graph. A forest is an undirected graph in which any two vertices are connected by ''at most one'' path, or equivalently an acyclic undirected graph, or equivalently a Disjoint union of graphs, disjoint union of trees. A polytreeSee . (or directed tree or oriented treeSee .See . or singly connected networkSee .) is a directed acyclic graph (DAG) whose underlying undirected graph is a tree. A polyforest (or directed forest or oriented forest) is a directed acyclic graph whose underlying undirecte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Undirected Graph
In discrete mathematics, and more specifically in graph theory, a graph is a structure amounting to a set of objects in which some pairs of the objects are in some sense "related". The objects correspond to mathematical abstractions called '' vertices'' (also called ''nodes'' or ''points'') and each of the related pairs of vertices is called an ''edge'' (also called ''link'' or ''line''). Typically, a graph is depicted in diagrammatic form as a set of dots or circles for the vertices, joined by lines or curves for the edges. Graphs are one of the objects of study in discrete mathematics. The edges may be directed or undirected. For example, if the vertices represent people at a party, and there is an edge between two people if they shake hands, then this graph is undirected because any person ''A'' can shake hands with a person ''B'' only if ''B'' also shakes hands with ''A''. In contrast, if an edge from a person ''A'' to a person ''B'' means that ''A'' owes money to ''B'', th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dual Graph
In the mathematical discipline of graph theory, the dual graph of a plane graph is a graph that has a vertex for each face of . The dual graph has an edge for each pair of faces in that are separated from each other by an edge, and a self-loop when the same face appears on both sides of an edge. Thus, each edge of has a corresponding dual edge, whose endpoints are the dual vertices corresponding to the faces on either side of . The definition of the dual depends on the choice of embedding of the graph , so it is a property of plane graphs (graphs that are already embedded in the plane) rather than planar graphs (graphs that may be embedded but for which the embedding is not yet known). For planar graphs generally, there may be multiple dual graphs, depending on the choice of planar embedding of the graph. Historically, the first form of graph duality to be recognized was the association of the Platonic solids into pairs of dual polyhedra. Graph duality is a topological ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
