Sciweavers

DM
2008
98views more  DM 2008»
13 years 11 months ago
Constructing equidissections for certain classes of trapezoids
We investigate equidissections of a trapezoid T(a), where the ratio of the lengths of two parallel sides is a. (An equidissection is a dissection into triangles of equal areas.) A...
Charles H. Jepsen, Paul Monsky
DM
2008
106views more  DM 2008»
13 years 11 months ago
Chromatic capacity and graph operations
The chromatic capacity cap(G) of a graph G is the largest k for which there exists a k-coloring of the edges of G such that, for every coloring of the vertices of G with the same ...
Jack Huizenga
DM
2008
63views more  DM 2008»
13 years 11 months ago
All triples for orthogonal designs of order 40
The use of amicable sets of eight circulant matrices and four negacyclic matrices to generate orthogonal designs is relatively new. We find all 1841 possible orthogonal designs of...
Wolf H. Holzmann, Hadi Kharaghani, Behruz Tayfeh-R...
DM
2008
104views more  DM 2008»
13 years 11 months ago
Improved upper and lower bounds on the feedback vertex numbers of grids and butterflies
We improve upon the best known upper and lower bounds on the sizes of minimal feedback vertex sets in butterflies. Also, we construct new feedback vertex sets in grids so that for...
Florent R. Madelaine, Iain A. Stewart
DM
2008
125views more  DM 2008»
13 years 11 months ago
Difference systems of sets and cyclotomy
Difference Systems of Sets (DSS) are combinatorial configurations that arise in connection with code synchronization. A method for the construction of DSS from partitions of cycli...
Yukiyasu Mutoh, Vladimir D. Tonchev
DM
2008
79views more  DM 2008»
13 years 11 months ago
The reconstruction conjecture and edge ideals
Given a simple graph G on n vertices, we prove that it is possible to reconstruct several algebraic properties of the edge ideal from the deck of G, that is, from the collection o...
Kia Dalili, Sara Faridi, Will Traves
DM
2008
61views more  DM 2008»
13 years 11 months ago
Inheritance of hyper-duality in imprimitive Bose-Mesner algebras
We prove the following result concerning the inheritance of hyper-duality by block and quotient Bose-Mesner algebras associated with a hyper-dual pair of imprimitive Bose-Mesner a...
Brian Curtin
DM
2008
75views more  DM 2008»
13 years 11 months ago
A new characterization of HH-free graphs
Dieter Kratsch, Jeremy Spinrad, R. Sritharan
DM
2008
94views more  DM 2008»
13 years 11 months ago
Discrete transformation hypergroups and transformation hypergroups with phase tolerance space
Tolerance spaces and algebraic structures with compatible tolerances play an important role in contemporary algebra and their applications. In this contribution we are presenting ...
Sárka Hosková, Jan Chvalina