In the context of fractal geometry, the natural extension of volume in Euclidean space is given by Hausdorff and packing measures. These measures arise naturally in the context of iterated function systems (IFS). For example, if the IFS is finite and conformal, then the Hausdorff and packing dimensions of the limit sets agree and the corresponding Hausdorff and packing measures are positive and finite. Moreover, the map which takes the IFS to its dimension is continuous. Developing on previous work, we show that the map which takes a finite conformal IFS to the numerical value of its packing measure is continuous. In the context of self-similar sets, we introduce the super separation condition. We then combine this condition with known density theorems to get a better handle on finding balls of maximum density. This allows us to extend the work of others and give exact formulas for the numerical value of packing measure for classes of Cantor sets, Sierpinski N-gons, and Sierpinski simplexes.

The subject of fractal geometry has exploded over the past 40 years with the availability of computer generated images. It was seen early on that there are many interesting questions at the intersection of probability and fractal geometry. In this dissertation we will introduce two random models for constructing fractals and prove various facts about them.

We investigate some relations between number theory and spectral measures related to the harmonic analysis of a Cantor set. Specifically, we explore ways to determine when an odd natural number m generates a complete or incomplete Fourier basis for a Cantor-type measure with scale g.

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The German Protestant church composer and organist, Gottfried August Homilius (1714-1785), is recognized primarily for his sacred compositions written during his time as cantor at the Kreuzkirche and the director of music at the three main churches in Dresden. The forerunner of Homilius research, Uwe Wolf, together with Carus-Verlag, brought forth Gottfried August Homilius: Studien zu Leben und Werk mit Werkverzeichnis (2008) and his thematic catalogue (2014) as products of the public’s renewed interest and research in the composer and his music. Homilius’ oratorio passion, Johannespassion, represents one of the valuable discoveries of this recent revival of Homilius research. While musicologists celebrate such an exciting expansion of the music library of the mid-eighteenth century, a bigger task ensues before us: the equal sharing of joy with the performers. Indeed, the resonance of Homilius’ music in the concert halls and churches beyond the bounds of the research papers and music p / Music Performance

Tesis por compendio / The diffractive optical elements have enhanced his importance in the last decades due to the improvement of the technology which allows its construction and the greater computing power that helps predicting the behaviour of the diffractive structures in function of the design parameters without en extra cost. The periodic symmetry become a key factor in order to understand the performance of these elements, and it allows to study the properties and the applicability of the different diffractive elements. However, this periodicity also introduces certain limitation in the design of the elements and their properties, such as high chromatic aberration when they are used as image forming elements. To overcome this limitations it was proposed the use of deterministic aperiodic sequences in the design of the diffractive optical elements. In this Thesis work I study different aperiodic sequences and their effect in the design of new diffractive structures. In particular, we use the Cantor fractal set, the Fibonacci sequence and the Thue--Morse series in the design of devices with different purposes. Along the development of the Thesis there have been generated new diffractive elements which overcome some limitations, opening new field for the application of pre-existing technologies. Between them, they can be highlighted the optical alignment systems, the generation of optical vortex, the reduction of the chromatic aberration and the enhancement of the focal depth in image forming elements. / Los elementos ópticos difractivos han ganado importancia en las últimas décadas debido al avance de la tecnología que permite su construcción y al aumento de la potencia de cálculo computacional que permite predecir, con un coste mínimo, su comportamiento en función de los múltiples parámetros que definen su estructura. La periodicidad constituye un factor clave a la hora de entender su funcionamiento y estudiar las propiedades y aplicabilidad de los diferentes tipos de elementos difractivos. Ahora bien, esta periodicidad también introduce ciertas limitaciones en el diseño de los elementos y en sus propiedades, como por ejemplo una alta aberración cromática al ser utilizados como elementos formadores de imagen. Para superar estas limitaciones se propuso la aplicación de secuencias aperiódicas deterministas al diseño de los elementos ópticos difractivos. En este trabajo de Tesis se han estudiado diferentes secuencias aperiódicas y sus efectos en el diseño de nuevas estructuras difractivas. En particular, se ha utilizado la secuencia fractal de Cantor, la serie de Fibonacci y la serie de Thue--Morse en el diseño de dispositivos difractivos con diferentes finalidades. A lo largo del desarrollo del trabajo de Tesis se han generado nuevos elementos difractivos que superan ciertas limitaciones, abriendo nuevos campos de aplicación a tecnologías preexistentes. Entre ellos, podemos destacar los sistemas de alineación óptica, la generación de vórtices ópticos, la reducción de la aberración cromática y el aumento de la profundidad de foco en elementos formadores de imagen. / Els elements òptics difractius han guanyat importancia les últimes dècades degut a l'avanç de la tecnología que permet la seua construcció y a l'augment de la potència de càlcul computacional que permet predir, amb un cost mínim, el seu comportament en funció dels diferents parámetres que defineixen la seua estructura. La periodicitat constitueix un factor clau a l'hora d'entendre el seu funcionament y estudiar les propietats y aplicabilitat dels diferents tipus d'elements difractius. Ara be, aquesta periodicitat tambe introdueix certes llimitacions en el disseny dels elements y les seus propietats, com per exemple una elevada aberració cromàtica quan actuen com a elements formadors d'imatges. Per superar aquestes llimitacions es va proposar l'aplicació de diferents sequencies aperiòdiques deterministes al disseny dels elements òptics difractius. En aquest treball de Tesi estudie diferents sequencies aperiòdiques y els seus efectes en el disseny de noves estructures difractives. En particular, s'han utilitzat la secuencia fractal de Cantor, la serie de Fibonacci y la serie de Thue--Morse en el disseny de dispositius difractius amb diferents finalitats. Al llarg del desenvolupament del treball de Tesi s'han generat nous elements difractius que superen certes llimitacions, obint nous camps d'aplicació a tecnologies preexistents. Entre ells, podem destacar els sistemes d'alineació òptica, la generació de vòrtex òptics, la reducció de l'aberració cromàtica y l'augment de la profunditat de fòcus d'elements formadors d'imatges. / Ferrando Martín, V. (2017). Diseño y aplicaciones de nuevas estructuras difractivas aperiódicas [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/79508 / Premios Extraordinarios de tesis doctorales / Compendio

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Les structures menues apparaissent dans les années 60 en lien avec la conjecture de Vaught. Les structures minces englobent à la fois les structures minimales et menues. Les ensembles définissables d'une structure mince sont rangés par le rang de Cantor-Bendixson. Nous présentons des propriétés de calcul de ce rang, une condition de chaîne descendante locale sur les groupes acl(0)-définissables ainsi qu'une notion de presque stabilisateur local, et en déduisons des propriétés algébriques des structures minces : un corps mince de caractéristique positive est localement de dimension finie sur son centre, et un groupe mince infini a un sous groupe abélien infini. Nous nous intéressons ensuite aux structures menues infiniment définissables, et montrons que les groupes d'arité finie infiniment 0-définissable sont l'intersection de groupes définissables. Nous étendons le résultat aux demi-groupes, anneaux, corps, catégories et groupoïdes infiniment 0-définissables, et donnons des résultats de définissabilité locale pour les groupes et corps simples et menus, infiniment définissables sur des paramètres quelconques. Enfin, nous réintroduisons le rang de Cantor dans son contexte topologique et montrons que la dérivée de Cantor peut être vue comme un opérateur de dérivation dans un semi-anneau d'espaces topologiques. Dans l'idée de trouver un rang de Cantor global pour les théories stables, nous essayons de nous débarrasser du mot dénombrable omniprésent lorsque l'on fait de la topologie, en le remplaçant par un cardinal régulier k. Nous développons une notion d'espace k-métrique, de k-topologie, de k-compacité etc. et montrons un k-analogue du lemme de métrisabilité d'Urysohn, et du théorème de Cantor-Bendixson. / Abstract. Small structures appear in the '60s together with Vaught's conjecture. Weakly small structures include both minimal and small structures. Definable sets in a weakly small structure are ranked by Cantor-Bendixson rank. We show computational properties of this rank, which imply a local descending chain condition on acl(0)-definable subgroups, and introduce a notion of local almost stabiliser. We deduce algebraic properties of weakly small structures. Among them, a weakly small field of positive characteristic is locally finite dimensional over its centre, and an infinite weakly small group has an infinite abelian subgroup. We then turn to small type-definable structures, showing that finitary small type 0-de_nable groups are the intersection of definable groups. We extend the result to finitary small type 0- definable monoids, rings, fields, categories and groupoids. We give local definability results concerning groups and fields type definable over an arbitrary set of parameters in small and simple theories. Finally, we reintroduce the Cantor Bendixson rank in its topological context, and show that the Cantor derivative can be seen as a derivation in a semi-ring of topological spaces. In an attempt to find a global Cantor rank for stable structures, we try to eliminate the word denumerable, omnipresent when one does topology, by replacing it by a regular cardinal k. We develop the notions of k-metrisable space, k-topology, k-compactness etc. and show an analogue of Urysohn's metrisability lemma and Cantor-Bendixson theorem.

<p>Fractal analysis is an important tool when we need to study geometrical objects less regular than ordinary ones, e.g. a set with a non-integer dimension value. It has developed intensively over the last 30 years which gives a hint to its young age as a branch within mathematics.</p><p>In this thesis we take a look at some basic measure theory needed to introduce certain definitions of fractal dimensions, which can be used to measure a set's fractal degree. Comparisons of these definitions are done and we investigate when they coincide. With these tools different fractals are studied and compared.</p><p>A key idea in this thesis has been to sum up different names and definitions referring to similar concepts.</p>

Fractal analysis is an important tool when we need to study geometrical objects less regular than ordinary ones, e.g. a set with a non-integer dimension value. It has developed intensively over the last 30 years which gives a hint to its young age as a branch within mathematics. In this thesis we take a look at some basic measure theory needed to introduce certain definitions of fractal dimensions, which can be used to measure a set's fractal degree. Comparisons of these definitions are done and we investigate when they coincide. With these tools different fractals are studied and compared. A key idea in this thesis has been to sum up different names and definitions referring to similar concepts.