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Finite subgroups of the extended Morava stabilizer groups / Sous-groupes finis des groupes de stabilisateur étendus de MoravaBujard, Cédric 04 June 2012 (has links)
L'objet de la thèse est la classification à conjugaison près des sous-groupes finis du groupe de stabilisateur (classique) de Morava S_n et du groupe de stabilisateur étendu G_n(u) associé à une loi de groupe formel F de hauteur n définie sur le corps F_p à p éléments. Une classification complète dans S_n est établie pour tout entier positif n et premier p. De plus, on montre que la classification dans le groupe étendu dépend aussi de F et son unité associée u dans l'anneau des entiers p-adiques. On établit un cadre théorique pour la classification dans G_n(u), on donne des conditions nécessaires et suffisantes sur n, p et u pour l'existence dans G_n(u) d'extensions de sous-groupes finis maximaux de S_n par le groupe de Galois de F_{p^n} sur F_p, et lorsque de telles extensions existent on dénombre leurs classes de conjugaisons. On illustre nos méthodes en fournissant une classification complète et explicite dans le cas n=2. / The problem addressed is the classification up to conjugation of the finite subgroups of the (classical) Morava stabilizer group S_n and the extended Morava stabilizer group G_n(u) associated to a formal group law F of height n over the field F_p of p elements. A complete classification in S_n is provided for any positive integer n and prime p. Furthermore, we show that the classification in the extended group also depends on F and its associated unit u in the ring of p-adic integers. We provide a theoretical framework for the classification in G_n(u), we give necessary and sufficient conditions on n, p and u for the existence in G_n(u) of extensions of maximal finite subgroups of S_n by the Galois group of F_{p^n} over F_p, and whenever such extension exist we enumerate their conjugacy classes. We illustrate our methods by providing a complete and explicit classification in the case n=2.
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Získávání informací o uživatelích na webových stránkách / Browser and User Fingerprinting for Practical DeploymentVondráček, Tomáš January 2021 (has links)
The aim of the diploma thesis is to map the information provided by web browsers, which can be used in practice to identify users on websites. The work focuses on obtaining and subsequent analysis of information about devices, browsers and side effects caused by web extensions that mask the identity of users. The acquisition of information is realized by a designed and implemented library in the TypeScript language, which was deployed on 4 commercial websites. The analysis of the obtained information is carried out after a month of operation of the library and focuses on the degree of information obtained, the speed of obtaining information and the stability of information. The dataset shows that up to 94 % of potentially different users have a unique combination of information. The main contribution of this work lies in the created library, design of new methods of obtaining information, optimization of existing methods and the determination of quality and poor quality information based on their level of information, speed of acquisition and stability over time.
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Lipschitz Structure of Metric and Banach SpacesQuilis Sandemetrio, Andrés 04 December 2023 (has links)
[ES] Desde el comienzo de la Teoría de Espacios de Banach, el estudio de los subespacios complementados y no complementados ha sido uno de los principales temas del área. Específicamente, en espacios de Banach no separables, han habido grandes esfuerzos en construir un marco teórico para describir la estructura de subespacios linealmente complementados en espacios de Banach. Concepctos clásicos como la Propiedad del Complemento Separable, Resoluciones Proyectivas de la Identidad, y la Propiedad de Plichko han sido y continúan siendo estudiadas en esta disciplina. En igual medida, las aplicaciones de Lipschitz en espacios de Banach también han jugado un papel importante en el desarrollo de la teoría. Cuestiones como la clasificación de Lipschitz de los espacios de Banach, la diferenciabilidad de las funciones de Lipschitz, o la existencia de retracciones de Lipschitz a subconjuntos y subespacios de espacios de Banach, son líneas de investigación activas con abundantes resultados y aplicaciones. En esta tesis analizamos la estructura de retractos de Lipschitz en espacios métricos y espacios de Banach no separables, de forma análoga a la teoría de complementación lineal en espacios de Banach. También discutimos la conexión de este tema con el progreso actual en el estudio de la estructura de los espacios de Lipschitz-free, y con el problema de la existencia de operadores de extensión lineales para funciones de Lipschitz. En primer lugar, generalizamos algunas herramientas clásicas de la teoría lineal al marco no lineal: Definimos el concepto de esqueletos retractivos de Lipschitz como una generalización a los esqueletos proyectivos. Como aplicación de estas nociones, demostramos que el espacio de Lipschitz-free asociado a un espacio de Banach con la propiedad de Plichko tiene a su vez la propiedad de Plichko. Utilizamos también los esqueletos retractivos de Lipschitz para caracterizar aquellos espacios métricos cuyo espacio de Lipschitz-free tiene la propiedad de Plichko con medidas de Dirac, y mostramos que el espacio de Lipschitz-free asociado a cualquier R-árbol es 1-Plichko con moléculas elementales. A continuación, pasamos a definir la Propiedad del Retracto de Lipschitz (α, β) (o la Lipschitz RP(α, β)) para un par de cardinales infinitos α ≤ β. Esta es la propiedad no lineal análoga a la clásica Propiedad del Complemento. Observamos que los espacios C(K) tiene la Lipschitz RP(ℵ0, ℵ0), lo cual implica que sus espacios de Lipschitz-free asociados poseen la Propiedad del Complemento Separable. Siguiendo con el estudio previo, construimos, para cada cardinal infinito Λ, un espacio métrico completo sin la Lipschitz RP(Λ, Λ)). En el caso numerable, podemos mejorar este resultado produciendo un espacio métrico completo que satisface una propiedad más fuerte que la negación de la Lipschitz RP(ℵ0, ℵ0): Todo subconjunto separable con almenos dos puntos no es un retracto de Lipschitz. Finalmente, generalizamos un resultado de Heinrich y Mankiewicz al marco no lineal al mostrar que en cada espacio métrico M, todo subconjunto está contenido en otro subconjunto con el mismo carácter de densidad que además admite un operador lineal de extensión de funciones Lipschitz. / [CA] Des del principi de la Teoria d'Espais de Banach, l'estudi dels subespais complementats i no complementats ha estat un dels principals temes de l'àrea. Específicament, en espais de Banach no separables, hi ha hagut un gran esforç de construir un marc teòric per descriure l'estructura de subespais linealment complementats en espais de Banach. Conceptes clàssics com la Propietat del Complement Separable, Resolucions Projectives de la Identitat, i la Propietat de Plichko han estat i continuen sent estudiades en aquesta disciplina. En igual mesura, les aplicacions de Lipschitz en espais de Banach també han jugat un paper important en el desenvolupament de la teoria. Qüestions com la classificació de Lipschitz dels espais de Banach, la diferenciabilitat de les funcions de Lipschitz, o l'existència de retraccions de Lipschitz a subconjunts i subespais d'espais de Banach, són línies d'investigació actives amb abundants resultats i aplicacions. En aquesta tesi analitzem l'estructura de retractes de Lipschitz en espais mètrics i espais de Banach no separables, de manera anàloga a la teoria de complementació lineal en espais de Banach. També discutim la connexió d'aquest tema amb el progrés actual en l'estudi de l'estructura dels espais de Lipschitz-free, i amb el problema de l'existència d'operadors d'extensió lineals per a funcions de Lipschitz. En primer lloc, generalitzem algunes eines clàssiques de la teoria lineal al marc no lineal: Definim el concepte d'esquelets retractius de Lipschitz com una generalització dels esquelets projectius. Com aplicació d'aquestes nocions, demostrem que l'espai de Lipschitz-free associat a un espai de Banach amb la propietat de Plichko té la propietat de Plichko. Utilitzem també els esquelets retractius de Lipschitz per a caracteritzar aquells espais mètrics que generen espais de Lipschitz-free amb la propietat de Plichko amb mesures de Dirac, i mostrem que l'espai de Lipschitz-free associat a qualsevol R-arbre és 1-Plichko amb molècules elementals. A continuació, passem a definir la Propietat del Retracte de Lipschitz (α, β) (o la Lipschitz RP(α, β)) per a un parell de cardinals infinits α ≤ β. Aquesta és la propietat no lineal anàloga a la clàssica Propietat del Complement. Observem que els espais C(K) tenen la Lipschitz RP(ℵ0, ℵ0), la qual cosa implica que els espais de Lipschitz-free associats posseeixen la Propietat del Complement Separable. Seguint amb l'estudi previ, construïm, per a cada cardinal infinit Λ, un espai mètric complet sense la Lipschitz RP(Λ, Λ). En el cas numerable, podem millorar aquest resultat produint un espai mètric complet que satisfà una propietat més forta que la negació de la Lipschitz RP(ℵ0, ℵ0): Tot subconjunt separable amb almenys dos punts no és un retracte de Lipschitz. Finalment, generalitzem un resultat de Heinrich i Mankiewicz al marc no lineal al demostrar que en cada espai mètric M, tot subconjunt està contingut en altre subconjut amb el mateix caràcter de densitat que a més admet un operador lineal d'extensió de funcions Lipschitz. / [EN] Since the inception of Banach Space Theory, the study of complemented and uncomplemented subspaces of Banach spaces has been one of the main themes of the area. Specifically, in non-separable Banach spaces, there have been many efofrts in constructing a theoretical framework to describe the linear complementation structure of Banach spaces. Classical concepts such as the Separable Complementation Property, Projectional Resolutions of the Identity, and the Plichko Property have been and continue to be studied in this area. Similarly, Lipschitz maps between Banach spaces have also played a main role in the development of the theory. Questions such as the Lipschitz classification of Banach spaces, difefrentiability of Lipschitz maps, or the existence of Lipschitz retractions onto subsets and subspaces of Banach spaces, have been and continue to be active topics of research with a wealth of results and applications. In this thesis we analyse the Lipschitz retractional structure of non-separable metric and Banach spaces, as an analogous theory to the linear complementation one in Banach spaces. We also discuss the connection of this topic with the ongoing program to study the structure of Lipschitz-free Banach spaces, and to the problem of finding bounded linear extension operators for Lipschitz functions. First, we generalize some classical tools of the linear theory to the non-linear setting: We define the concept of Lipschitz retractional skeletons as a generalization of Projectional skeletons. As applications of these concepts, we show that the Lipschitz-free space of a Plichko Banach space is again Plichko. We also use Lipschitz retractional skeletons to characterize metric spaces whose Lipschitz-free spaces enjoy the Plichko property witnessed by Dirac measures, and we show that the Lipschitz-free space of any R-tree is 1-Plichko witnessed by molecules. Next, we pass on to defining the (α, β) Lipschitz Retraction Property (Lipschitz RP(α, β) for short) for a pair of infinite cardinals α ≤ β. These are the non-linear analogues to the classical Complementation Properties. We observe that C(K) spaces enjoy the Lipschitz RP(ℵ0, ℵ0), which in turn implies that their associated Lipschitz-free space satisfy the Separable Complementation Property. As a continuation of the previous study, we construct, for every infinite cardinal Λ, a complete metric space which fails the Lipschitz RP(Λ, Λ). In the countable case, we are able to produce a complete metric space, called the skein space, with a stronger property than the negation of the Lipschitz RP(ℵ0, ℵ0): Every separable subset of the skein space with at least two points fails to be a Lipschitz retract. Finally, we generalize a result of Heinrich and Mankiewicz to the non-linear setting, by showing that for any metric space M, every subset is contained in another subset of the same density character which admits a bounded linear extension operator for the space of Lipschitz functions. / Quilis Sandemetrio, A. (2023). Lipschitz Structure of Metric and Banach Spaces [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/200447
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EXPANDED CHOREOGRAPHY : Shifting the agency of movement in The Artificial Nature Project and 69 positionsInvartsen, Mette January 2016 (has links)
Through two books and a series of video documentations of live performances Mette Ingvartsen makes choreography into a territory of physical, artistic and social experimentation. The Artificial Nature Series focusses on how relations between human and non-human agency can be explored and reconfigured through choreography. By investigating and creating a ‘nonhuman theater’ questions regarding material agency, ecology, natural disasters, the Anthropocene and non-subjective performativity are posed. The resulting reflections are closely related to the poetic principles utilized to create the performances, while also drawing connections to territories outside theater. By contrast, 69 positions inscribes itself into a history of human performance with afocus on nudity, sexuality and how the body historically has been a site for political struggles. By creating a guided tour through sexual performances – from the naked protest actions of the 1960’s, through an archive ofpersonal performances into a reflection on contemporary sexual practice – this solo work rethinks audience participation and proposes a notion of soft and social choreography. The contrasting performative strategiesarticulate a twofold notion of expanded choreography: on the one hand movement is extended beyond the human body by including the agency of nonhuman performers, and on the other hand, movement is expanded into animaginary and virtual space thanks to ‘language choreography’. / <p>LINKS</p><p>https://vimeo.com/164552586</p><p>https://vimeo.com/164558381</p>
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Shift gray codesWilliams, Aaron Michael 11 December 2009 (has links)
Combinatorial objects can be represented by strings, such as 21534 for the permutation (1 2) (3 5 4), or 110100 for the binary tree corresponding to the balanced parentheses (()()). Given a string s = s1 s2 sn, the right-shift operation shift(s, i, j) replaces the substring si si+1..sj by si+1..sj si. In other words, si is right-shifted into position j by applying the permutation (j j−1 .. i) to the indices of s. Right-shifts include prefix-shifts (i = 1) and adjacent-transpositions (j = i+1). A fixed-content language is a set of strings that contain the same multiset of symbols. Given a fixed-content language, a shift Gray code is a list of its strings where consecutive strings differ by a shift. This thesis asks if shift Gray codes exist for a variety of combinatorial objects. This abstract question leads to a number of practical answers.
The first prefix-shift Gray code for multiset permutations is discovered, and it provides the first algorithm for generating multiset permutations in O(1)-time while using O(1) additional variables. Applications of these results include more efficient exhaustive solutions to stacker-crane problems, which are natural NP-complete traveling salesman variants. This thesis also produces the fastest algorithm for generating balanced parentheses in an array, and the first minimal-change order for fixed-content necklaces and Lyndon words.
These results are consequences of the following theorem: Every bubble language has a right-shift Gray code. Bubble languages are fixed-content languages that are closed under certain adjacent-transpositions. These languages generalize classic combinatorial objects: k-ary trees, ordered trees with fixed branching sequences, unit interval graphs, restricted Schr oder and Motzkin paths, linear-extensions of B-posets, and their unions, intersections, and quotients. Each Gray code is circular and is obtained from a new variation of lexicographic order known as cool-lex order.
Gray codes using only shift(s, 1, n) and shift(s, 1, n−1) are also found for multiset permutations. A universal cycle that omits the last (redundant) symbol from each permutation is obtained by recording the first symbol of each permutation in this Gray code. As a special case, these shorthand universal cycles provide a new fixed-density analogue to de Bruijn cycles, and the first universal cycle for the "middle levels" (binary strings of length 2k + 1 with sum k or k + 1).
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Complexity of Normal Forms on Structures of Bounded DegreeHeimberg, Lucas 04 June 2018 (has links)
Normalformen drücken semantische Eigenschaften einer Logik durch syntaktische Restriktionen aus. Sie ermöglichen es Algorithmen, Grenzen der Ausdrucksstärke einer Logik auszunutzen. Ein Beispiel ist die Lokalität der Logik erster Stufe (FO), die impliziert, dass Graph-Eigenschaften wie Erreichbarkeit oder Zusammenhang nicht FO-definierbar sind. Gaifman-Normalformen drücken die Bedeutung einer FO-Formel als Boolesche Kombination lokaler Eigenschaften aus. Sie haben eine wichtige Rolle in Model-Checking Algorithmen für Klassen dünn besetzter Graphen, deren Laufzeit durch die Größe der auszuwertenden Formel parametrisiert ist. Es ist jedoch bekannt, dass Gaifman-Normalformen im Allgemeinen nur mit nicht-elementarem Aufwand konstruiert werden können. Dies führt zu einer enormen Parameterabhängigkeit der genannten Algorithmen. Ähnliche nicht-elementare untere Schranken sind auch für Feferman-Vaught-Zerlegungen und für die Erhaltungssätze von Lyndon, Łoś und Tarski bekannt.
Diese Arbeit untersucht die Komplexität der genannten Normalformen auf Klassen von Strukturen beschränkten Grades, für welche die nicht-elementaren unteren Schranken nicht gelten. Für diese Einschränkung werden Algorithmen mit elementarer Laufzeit für die Konstruktion von Gaifman-Normalformen, Feferman-Vaught-Zerlegungen, und für die Erhaltungssätze von Lyndon, Łoś und Tarski entwickelt, die in den ersten beiden Fällen worst-case optimal sind.
Wichtig hierfür sind Hanf-Normalformen. Es wird gezeigt, dass eine Erweiterung von FO durch unäre Zählquantoren genau dann Hanf-Normalformen erlaubt, wenn alle Zählquantoren ultimativ periodisch sind, und wie Hanf-Normalformen in diesen Fällen in elementarer und worst-case optimaler Zeit konstruiert werden können.
Dies führt zu Model-Checking Algorithmen für solche Erweiterungen von FO sowie zu Verallgemeinerungen der Algorithmen für Feferman-Vaught-Zerlegungen und die Erhaltungssätze von Lyndon, Łoś und Tarski. / Normal forms express semantic properties of logics by means of syntactical restrictions. They allow algorithms to benefit from restrictions of the expressive power of a logic. An example is the locality of first-order logic (FO), which implies that properties like reachability or connectivity cannot be defined in FO. Gaifman's local normal form expresses the satisfaction conditions of an FO-formula by a Boolean combination of local statements. Gaifman normal form serves as a first step in fixed-parameter model-checking algorithms, parameterised by the size of the formula, on sparse graph classes. However, it is known that in general, there are non-elementary lower bounds for the costs involved in transforming a formula into Gaifman normal form. This leads to an enormous parameter-dependency of the aforementioned algorithms. Similar non-elementary lower bounds also hold for Feferman-Vaught decompositions and for the preservation theorems by Lyndon, Łoś, and Tarski.
This thesis investigates the complexity of these normal forms when restricting attention to classes of structures of bounded degree, for which the non-elementary lower bounds are known to fail. Under this restriction, the thesis provides
algorithms with elementary and even worst-case optimal running time for the construction of Gaifman normal form and Feferman-Vaught decompositions. For the preservation theorems, algorithmic versions with elementary running time and non-matching lower bounds are provided.
Crucial for these results is the notion of Hanf normal form. It is shown that an extension of FO by unary counting quantifiers allows Hanf normal forms if, and only if, all quantifiers are ultimately periodic, and furthermore, how Hanf normal form can be computed in elementary and worst-case optimal time in these cases. This leads to model-checking algorithms for such extensions of FO and also allows generalisations of the constructions for Feferman-Vaught decompositions and preservation theorems.
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