Báo cáo toán học: "Isomorphism Classes of Maximal Intersecting Uniform Families Are Few" ppsx

... 29, 2005 Keywords: maximal intersecting; uniform antichains Abstract Denote by f (k, m) the number of isomorphism classes of m aximal intersecting k -uniform families of subsets of [m]. In this note ... 3, viz: the electronic journal of combinatorics 12 (2005), #R67 8 Isomorphism Classes of Maximal Intersecting Uniform Families Are Few Geoffrey McKenna Depar...

Ngày tải lên: 07/08/2014, 13:21

... parameters of σ. The parameters of the empty permutation (of length 0) are (1, 1). Note that for any permutation, p ≤ q. Lemma 10 ([37]) Let σ be a 1234-avoiding permutation of length n ≥ 0, of parameters (p, ... length and the label of the corresponding node of the tree. These equations are now well understood, and their solutions are always algebraic series. Several other...

Ngày tải lên: 07/08/2014, 07:21

... Wilf classes for single permutations of length 4, 5, 6, and 7 are known. There are, up to symmetry, 56 classes of pairs of permutations of length four. Numer- ical data in [4] shows that there are ... that begin with n and begin with a decreasing sequence of length k. This completes the proof of Theorem 2.  We now give the proof of Lemma 7. Proof of Lemma 7: It is kn...

Ngày tải lên: 07/08/2014, 08:22

... distribution of the equivalence classes of 2-cell embeddings of some graphs such as bouquets of circles and dipoles are known. However, the genus distribu- tion of congruence classes of 2-cell embeddings ... two embeddings ı and  are called equivalent. In other words, the equivalence (congruence resp.) classes of embeddings of a graph X is the isomorphism classes...

Ngày tải lên: 08/08/2014, 12:22

... studied. One type is the profile classes of Atkinson [6], which in our language are grid classes of permutation matrices. Another example of grid classes are the W -classes introduced by Atkinson, ... completing the proof. 2.4 The enumeration of grid classes To date only scattered results are known about the enumeration of grid classes and their subclasses. The only...

Ngày tải lên: 07/08/2014, 13:21

... properties of cyclic permu- tations of r. In Section 3, we consider more general cases. 2 Properties of cyclic permutations of a sequence In this section, we study pro perties of cyclic permutations of ... permutations of a sequence of vectors and uniformly partition sets of many new combinatorial structures. Based on the rightmost lowest point of a lattice path, Woan [24...

Ngày tải lên: 08/08/2014, 12:22

... exist 1. a number r ∈ (0, 1); 2. a sequence of complex numbers z n , |z n | < r; Further results of the estimate of growth of entire solutions of some classes of algebraic differential equations Qi ... text (HTML) versions will be made available soon. Further results of the estimate of growth of entire solutions of some classes of algebraic differential equations A...

Ngày tải lên: 20/06/2014, 20:20

... on the set of all finite permutations; sets of permutations which are closed downwards under this order are called permutation classes. These classes are specified primarily in one of three ways: • ... the the electronic journal of combinatorics 14 (2007), #R46 2 Wreath Products of Permutation Classes Robert Brignall School of Mathematics and Statistics University of St...

Ngày tải lên: 07/08/2014, 15:22

... existence of a Room frame of type 1 n−s s 1 is equivalent to the existence of an object called an (n, s)-incomplete Room square which is essentially a Room square of side n containing a Room square of ... t k u k denotes u i occurrences of t i , 1  i  k. We note that a Room square of side n is equivalent to a Room fr ame of type 1 n . Examples of Room frames of types 1 8...

Ngày tải lên: 08/08/2014, 12:22

... of the FWHM of L1 emission lines for a series of Mn concentrations. Figure 4. The emission intensity of the neutral acceptor-bound exciton line L1. The emission intensity is a function of ... around the vacancy site, thus softening the normal-mode frequencies of the lattice and reducing the zero-point energy of the oscillators. An increase in the number of Mn atoms in t...

Ngày tải lên: 20/06/2014, 20:20