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Pattern-avoiding permutation classes
Opler, Michal ; Jelínek, Vít (advisor) ; Klazar, Martin (referee)
For a permutation π, the major index of π is the sum of all indices i such that πi > πi+1. In this thesis, we study the distribution of the major index over pattern-avoiding permutations of length n. We focus on the number Mm n (Π) of permutations of length n with major index m and avoiding the set of patterns Π. First, we are able to show that for a singleton set Π = {σ} other than some trivial cases, the values Mm n (Π) are monotonic in the sense that Mm n (Π) ≤ Mm n+1(Π). Our main result is a study of the asymptotic behaviour of Mm n (Π) as n goes to infinity. We prove that for every fixed m, Π and n large enough, Mm n (Π) is equal to a polynomial in n and moreover, we are able to determine the degrees of these polynomials for many sets of patterns. 1
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Enumeration of compositions with forbidden patterns
Dodova, Borjana ; Klazar, Martin (advisor) ; Jelínek, Vít (referee)
Enumeration of pattern avoiding compositions of numbers Abstract The aim of this work was to find some new results for 3-regular compositions, i.e., for those compositions which avoid the set of patterns {121, 212, 11}. Those compositions can be regarded as a generalization of Carlitz composition. Based on the generating function of compositions avoiding the set of patterns {121, 11} and {212, 11} we derive an upper bound for the coefficients of the power series of the generating function of 3-regular compositions. Using the theory of finite automata we derive its lower bound. We develop this result further by defining 3-block compositions. For the generating function of 3-regular compositions we prove a recursive ralation. Besides that we also compute the generating function of compositions avoiding the set of patterns {312, 321} whose parts are in the set [d]. In the last section we prove that the generating function of Carlitz compositions is transcendental.
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Extremal combinatorics of matrices, sequences and sets of permutations
Cibulka, Josef ; Valtr, Pavel (advisor) ; Füredi, Zoltán (referee) ; Jelínek, Vít (referee)
Title: Extremal combinatorics of matrices, sequences and sets of permutations Author: Josef Cibulka Department: Department of Applied Mathematics Supervisor: Doc. RNDr. Pavel Valtr, Dr., Department of Applied Mathematics Abstract: This thesis studies questions from the areas of the extremal theory of {0, 1}-matrices, sequences and sets of permutations, which found many ap- plications in combinatorial and computational geometry. The VC-dimension of a set P of n-element permutations is the largest integer k such that the set of restrictions of the permutations in P on some k-tuple of positions is the set of all k! permutation patterns. We show lower and upper bounds quasiexponential in n on the maximum size of a set of n-element permutations with VC-dimension bounded by a constant. This is used in a paper of Jan Kynčl to considerably improve the upper bound on the number of weak isomorphism classes of com- plete topological graphs on n vertices. For some, mostly permutation, matrices M, we give new bounds on the number of 1-entries an n × n M-avoiding matrix can have. For example, for every even k, we give a construction of a matrix with k2 n/2 1-entries that avoids one specific k-permutation matrix. We also give almost tight bounds on the maximum number of 1-entries in matrices avoiding a fixed layered...
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Generating graphs
Mohelníková, Lucie ; Dvořák, Zdeněk (advisor) ; Jelínek, Vít (referee)
Title: Generating graphs Author: Lucie Mohelníková Department: Department of Applied Mathematics Supervisor: Mgr. Zdeněk Dvořák, Ph.D., Computer Science Institute of Char- les University Abstract: The main topic of this thesis are the methods used to generate graphs from prescribed classes, especially graphs embeddable in surfaces. An im- portant technique in this context is to generate the graphs by vertex decontracti- ons. The identification of initial (irreducible) graphs is crucial for this technique. We give an overview of the results regarding the irreducible triangulations and quadrangulations of various surfaces, especially the surfaces of low genus (sphere, projective plane, Klein bottle). The main result of this work is the identification 21 irreducible triangulations which proves the result of Lawrencenko without using of information technology. Keywords: irreducible, triangulations, torus
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Obecná enumerace číselných rozkladů
Hančl, Jaroslav ; Klazar, Martin (advisor) ; Jelínek, Vít (referee)
Název práce: Obecná enumerace číselných rozklad· Autor: Jaroslav Hančl Katedra: Katedra aplikované matematiky Vedoucí diplomové práce: doc. RNDr. Martin Klazar, Dr., KAM MFF UK Abstrakt: Předložená diplomová práce se zabývá asymptotikami počítacích funkcí ideál· číselných rozklad·. Jejím hlavním cílem je zjistit největší možný asympto- tický r·st počítací funkce rozkladového ideálu, která je nekonečněkrát rovna nule. Autor se na základě znalosti asymptotik vybraných rozkladových ideál· snaží po- mocí kombinatorických a základních analytických metod odvodit odhady hledané asymptotiky. Výsledkem je za prvé slabší horní odhad, za druhé poměrně silný dolní odhad a za třetí, pro speciální třídu rozkladových ideál· je nalezen největší asymptotický r·st. Klíčová slova: íselné rozklady, asymptotika rozklad·, rozkladové ideály, počítací funkce, kombinatorická enumerace. 1
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Algebraické vlastnosti barevnosti grafů
Bulánek, Jan ; Jelínek, Vít (referee) ; Kráľ, Daniel (advisor)
We study algebraic tools for proving the existence of graph colorings and focus a classical method of Alon-Tarsi from this area. In particular, we prove Alon-Tarsi Theorem, provide examples of some known applications and give a new application to colorings of squares of cycles.
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Editor matematických výrazů
Holaň, David ; Lidický, Bernard (referee) ; Jelínek, Vít (advisor)
In the present work we study the concept and implementation of "MaEd for LATEX", a portable graphical user interface program for creating and editing of LATEX formulae. The program is designed to allow a beginner to create even complex formulae without any knowledge of underlying LATEX source code. The user can also import his own source code and the program doesn't make unnecessary changes to the imported source code, like removing comments and indentation. The concept describes how was the program's GUI designed. The LATEX commands available for creation of math formulae are described along with their syntax and level of support in the program. The work also analyzes structure of LATEX source code.
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