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Wells Graph
The Wells graph is the unique distance-regular graph with intersection array \. Its spectrum is 5^1 \sqrt^8 1^ (-\sqrt)^8(-3)^5. Its queue number is 3 and an upper bound on its book thickness In graph theory, a book embedding is a generalization of planar embedding of a graph to embeddings in a ''book'', a collection of half-planes all having the same line as their boundary. Usually, the vertices of the graph are required to lie on ... is 5.Jessica Wolz, ''Engineering Linear Layouts with SAT''. Master Thesis, University of Tübingen, 2018 References {{Reflist External links A.E. Brouwer's website: The Armanios-Wells graph Individual graphs Regular graphs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Distance Regular Graph
In the mathematical field of graph theory, a distance-regular graph is a regular graph such that for any two vertices and , the number of vertices at distance from and at distance from depends only upon , , and the distance between and . Some authors exclude the complete graphs and disconnected graphs from this definition. Every distance-transitive graph is distance regular. Indeed, distance-regular graphs were introduced as a combinatorial generalization of distance-transitive graphs, having the numerical regularity properties of the latter without necessarily having a large automorphism group. Intersection arrays The intersection array of a distance-regular graph is the array ( b_0, b_1, \ldots, b_; c_1, \ldots, c_d ) in which d is the diameter of the graph and for each 1 \leq j \leq d , b_j gives the number of neighbours of u at distance j+1 from v and c_j gives the number of neighbours of u at distance j - 1 from v for any pair of vertices u and v at dis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hamiltonian Graph
In the mathematical field of graph theory, a Hamiltonian path (or traceable path) is a path in an undirected or directed graph that visits each vertex exactly once. A Hamiltonian cycle (or Hamiltonian circuit) is a cycle that visits each vertex exactly once. A Hamiltonian path that starts and ends at adjacent vertices can be completed by adding one more edge to form a Hamiltonian cycle, and removing any edge from a Hamiltonian cycle produces a Hamiltonian path. The computational problems of determining whether such paths and cycles exist in graphs are NP-complete; see Hamiltonian path problem for details. Hamiltonian paths and cycles are named after William Rowan Hamilton, who invented the icosian game, now also known as ''Hamilton's puzzle'', which involves finding a Hamiltonian cycle in the edge graph of the dodecahedron. Hamilton solved this problem using the icosian calculus, an algebraic structure based on roots of unity with many similarities to the quaternions (also in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Queue Number
In the mathematical field of graph theory, the queue number of a Graph (discrete mathematics), graph is a graph invariant defined analogously to book thickness, stack number (book thickness) using Queue (abstract data type), first-in first-out (queue) orderings in place of Stack (abstract data type), last-in first-out (stack) orderings. Definition A queue layout of a given graph is defined by a total ordering of the vertex (graph theory), vertices of the graph together with a partition of the edge (graph theory), edges into a number of "queues". The set of edges in each queue is required to avoid edges that are properly nested: if and are two edges in the same queue, then it should not be possible to have in the vertex ordering. The queue number of a graph is the minimum number of queues in a queue layout.. Equivalently, from a queue layout, one could process the edges in a single queue using a Queue (abstract data type), queue data structure, by considering the vertices in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Book Thickness
In graph theory, a book embedding is a generalization of planar embedding of a graph to embeddings in a ''book'', a collection of half-planes all having the same line as their boundary. Usually, the vertices of the graph are required to lie on this boundary line, called the ''spine'', and the edges are required to stay within a single half-plane. The book thickness of a graph is the smallest possible number of half-planes for any book embedding of the graph. Book thickness is also called pagenumber, stacknumber or fixed outerthickness. Book embeddings have also been used to define several other graph invariants including the pagewidth and book crossing number. Every graph with vertices has book thickness at most \lceil n/2\rceil, and this formula gives the exact book thickness for complete graphs. The graphs with book thickness one are the outerplanar graphs. The graphs with book thickness at most two are the subhamiltonian graphs, which are always planar; more generally, e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Individual Graphs
An individual is one that exists as a distinct entity. Individuality (or self-hood) is the state or quality of living as an individual; particularly (in the case of humans) as a person unique from other people and possessing one's own needs or goals, rights and responsibilities. The concept of an individual features in many fields, including biology, law, and philosophy. Every individual contributes significantly to the growth of a civilization. Society is a multifaceted concept that is shaped and influenced by a wide range of different things, including human behaviors, attitudes, and ideas. The culture, morals, and beliefs of others as well as the general direction and trajectory of the society can all be influenced and shaped by an individual's activities. Etymology From the 15th century and earlier (and also today within the fields of statistics and metaphysics) ''individual'' meant " indivisible", typically describing any numerically singular thing, but sometimes meani ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
