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Reconstruction of homogeneous relational structures
No full textWe give a result on the reconstruction of certain homogeneous transitive omega-categorical relational structures from their automorphism group. We use an approach developed by M. Rubin to show that for a range of such structures the abstract group structure of the automorphism group Aut(M) determines the topology on AUt(M) and hence the structure M up to bi-interpretability. Our methods involve the construction of a generic pair of automorphisms and applies to cases where a better known reconstruction approach, the small index property, either is not known to hold or does not apply
Model theory and extremal combinatorics
No full textThis thesis is concerned with combinatorial properties of homogeneous structures such as the Ramsey property, big Ramsey degrees, EPPA, and others. What these properties have in common is that, while being finitary problems on classes of finite structures, they are equivalent to various dynamical properties of automorphism groups of the cor- responding homogeneous structures. This thesis consists of an extended introduction to these areas, a list of open problems, and ten papers of which the author is a co-author, seven of which have been published at the time of writing this thesis, the other three have been submitted. The goal is to demonstrate that, at least on the combinatorial side of things, there are many interplays of these properties which can be (and have been) exploited to further each of the areas.
Teorie modelů a extremální kombinatorika
Full text linkThis thesis is concerned with combinatorial properties of homogeneous structures such as the Ramsey property, big Ramsey degrees, EPPA, and others. What these properties have in common is that, while being finitary problems on classes of finite structures, they are equivalent to various dynamical properties of automorphism groups of the cor- responding homogeneous structures. This thesis consists of an extended introduction to these areas, a list of open problems, and ten papers of which the author is a co-author, seven of which have been published at the time of writing this thesis, the other three have been submitted. The goal is to demonstrate that, at least on the combinatorial side of things, there are many interplays of these properties which can be (and have been) exploited to further each of the areas. 1Tato disertační práce se zabývá kombinatorickými vlastnostmi homogenních struk- tur, jako je například Ramseyova vlastnost, velké ramseyovské stupně, EPPA a další. Tyto vlastností mají společné, že přestože jsou to vlastnosti tříd konečných struktur, jsou ekvivalentní různým dynamickým vlastnostem grup automorfismů příslušných ho- mogenních struktur. Tato práce sestává z rozšířeného úvodu do těchto oblastí, seznamu otevřených problémů a deseti článků, jejichž je autor spoluautorem. Sedm z nich bylo již v době psaní této disertace publikováno, zbylé tři byly odeslané do časopisů k recen- znímu řízení. Cílem práce je ukázat, že (alespoň na straně konečné kombinatoriky) mezi výše zmíněnými vlastnostmi je mnoho souvislostí, jichž lze využít pro posun příslušných oblastí. 1Department of Applied MathematicsKatedra aplikované matematikyFaculty of Mathematics and PhysicsMatematicko-fyzikální fakult
S. Barry Cooper (1943-2015)
No full textThis article is an obituary in memoriam Barry Cooper (1943-2015
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Orbit equivalent infinite permutation groups
No full textNon UBCUnreviewedAuthor affiliation: University of LeedsFacult
Locally compact permutation groups, and maximal-closed permutation groups
No full textThe full symmetric group S on a countably infinite set X carries a natural topology, the topology of pointwise convergence. I will discuss joint work in progress with Cheryl Praeger and Simon Smith, and some open questions, on multiply transitive locally compact subgroups of S, on maximal-closed subgroups of S, and on subgroups of S which are maximal subject to being subdegree-finite.Non UBCUnreviewedAuthor affiliation: University of LeedsFacult
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