Dissertations / Theses: 'Median graphs'

1

Genevois, Anthony. "Cubical-like geometry of quasi-median graphs and applications to geometric group theory." Thesis, Aix-Marseille, 2017. http://www.theses.fr/2017AIXM0569/document.

Full text

Abstract:

La classe des graphes quasi-médians est une généralisation des graphes médians, ou de manière équivalente, des complexes cubiques CAT(0). L'objectif de cette thèse est d'introduire ces graphes dans le monde de la théorie géométrique des groupes. Dans un premier temps, nous étendons la notion d'hyperplan définie dans les complexes cubiques CAT(0), et nous montrons que la géométrie d'un graphe quasi-médian se réduit essentiellement à la combinatoire de ses hyperplans. Dans la deuxième partie de notre texte, qui est le cœur de la thèse, nous exploitons la structure particulière des hyperplans pour démontrer des résultats de combinaison. L'idée principale est que si un groupe agit d'une bonne manière sur un graphe quasi-médian de sorte que les stabilisateurs de cliques satisfont une certaine propriété P de courbure négative ou nulle, alors le groupe tout entier doit satisfaire P également. Les propriétés que nous considérons incluent : l'hyperbolicité (éventuellement relative), les compressions lp (équivariantes), la géométrie CAT(0) et la géométrie cubique. Finalement, la troisième et dernière partie de la thèse est consacrée à l'application des critères généraux démontrés précédemment à certaines classes de groupes particulières, incluant les produits graphés, les groupes de diagrammes introduits par Guba et Sapir, certains produits en couronne, et certains graphes de groupes. Les produits graphés constituent notre application la plus naturelle, où le lien entre le groupe et son graphe quasi-médian associé est particulièrement fort et explicite; en particulier, nous sommes capables de déterminer précisément quand un produit graphé est relativement hyperbolique
The class of quasi-median graphs is a generalisation of median graphs, or equivalently of CAT(0) cube complexes. The purpose of this thesis is to introduce these graphs in geometric group theory. In the first part of our work, we extend the definition of hyperplanes from CAT(0) cube complexes, and we show that the geometry of a quasi-median graph essentially reduces to the combinatorics of its hyperplanes. In the second part, we exploit the specific structure of the hyperplanes to state combination results. The main idea is that if a group acts in a suitable way on a quasi-median graph so that clique-stabilisers satisfy some non-positively curved property P, then the whole group must satisfy P as well. The properties we are interested in are mainly (relative) hyperbolicity, (equivariant) lp-compressions, CAT(0)-ness and cubicality. In the third part, we apply our general criteria to several classes of groups, including graph products, Guba and Sapir's diagram products, some wreath products, and some graphs of groups. Graph products are our most natural examples, where the link between the group and its quasi-median graph is particularly strong and explicit; in particular, we are able to determine precisely when a graph product is relatively hyperbolic

APA, Harvard, Vancouver, ISO, and other styles

2

Bénéteau, Laurine. "Médians de graphes : algorithmes, connexité et axiomatique." Electronic Thesis or Diss., Aix-Marseille, 2022. http://www.theses.fr/2022AIXM0512.

Full text

Abstract:

Le problème du médian est un des problèmes les plus étudiés en théorie des espaces métriques. Nous l'étudions dans les graphes médians d'un point de vue algorithmique. Nous présentons un algorithme linéaire basé sur un calcul rapide des classes de parallélisme des arêtes (les Thêta-classes) via un parcours en largeur particulier (LexBFS). Nous donnons également un algorithme linéaire pour le problème du médian dans les l1-complexes cubiques des graphes médians et dans les structures d'évènements.Ensuite, nous présentons une caractérisation des graphes aux médians connexes dans la p-ième puissance Gp du graphe et donnons une méthode polynomiale pour vérifier si un graphe est un graphe aux médians Gp-connexes, étendant un résultat de Bandelt et Chepoi (cas p=1). Nous utilisons cette caractérisation pour montrer que certaines classes de graphes sont G2-connexes, comme les graphes de Helly bipartis et les graphes pontés. Nous travaillons également sur l'aspect axiomatique en étudiant l'ABC-problème, qui consiste à déterminer les graphes (nommés ABC-graphes) dans lesquels la fonction médian est l'unique fonction consensus respectant trois axiomes simples (A) Anonymat, (B) Intervalle (Betweeness) et (C) Cohérence. Nous montrons que les graphes modulaires aux médians G2-connexes sont des ABC-graphes et définissons de nouveaux axiomes pour caractériser la fonction médian dans d'autres classes de graphes, comme les graphes aux médians connexes. Nous prouvons également que les graphes respectant la propriété d'appariement (qui sont des ABC-graphes) est une sous-classe propre des graphes de Helly bipartis et étudions la complexité de la reconnaissance de ces graphes
The median problem is one of the most investigated problem in metric graph theory. We will start by studying this problem in median graphs. We present a linear time algorithm based on the majority rule which characterize the median in median graphs and on a fast computation of the parallelism classes of the edges (the \Theta-classes) via LexBFS which is a particular breadth first search algorithm.We also provide linear time algorithms to compute the median set in the l_1-cube complexes of median graphs and in event structures. Then, we provide a characterization of the graphs with connected medians in the pth power of the graph and provide a polynomial method to check if a graph is a G^p-connected median graph, extending a result of Bandelt and Chepoi (case p=1). We use this characterization to prove that some important graph classes in metric graph theory have G2-connected medians, such as bipartite Helly graphs and bridged graphs. We will also studied the axiomatic aspect of the median function by investigating the ABC-problem, which determine the graphs (named ABC-graphs) in which the median function is the only consensus function verifying three simples axioms (A) Anonymat, (B) Betweeness and (C) Consistency. We show that modular graphs with G2-connected medians are ABC-graphs and define new axioms allowing us to characterize the median function on some graph classes. For example the graphs with connected medians (including Helly graphs). We also show that a known class of ABC-graphs (graphs satisfying the pairing property) is a proper subclass of bipartite Helly graphs and we investigate their recognition

APA, Harvard, Vancouver, ISO, and other styles

3

Ren, Haolin. "Visualizing media with interactive multiplex networks." Thesis, Bordeaux, 2019. http://www.theses.fr/2019BORD0036/document.

Full text

Abstract:

Les flux d’information suivent aujourd’hui des chemins complexes: la propagation des informations, impliquant éditeurs on-line, chaînes d’information en continu et réseaux sociaux, emprunte alors des chemins croisés, susceptibles d’agir sur le contenu et sa perception. Ce projet de thèse étudie l’adaptation des mesures de graphes classiques aux graphes multiplexes en relation avec le domaine étudié, propose de construire des visualisations à partir de plusieurs représentations graphiques des réseaux, et de les combiner (visualisations multi-vues synchronisées, représentations hybrides, etc.). L’accent est mis sur les modes d’interaction permettant de prendre en compte l’aspect multiplexe (multicouche) des réseaux. Ces représentations et manipulations interactives s’appuient aussi sur le calcul d’indicateurs propres aux réseaux multiplexes. Ce travail est basé sur deux jeux de données principaux: l’un est une archive de 12 ans de l’émission japonaise publique quotidienne NHK News 7, de 2001 à 2013. L’autre recense les participants aux émissions de télévision/radio françaises entre 2010 et 2015. Deux systèmes de visualisation s’appuyant sur une interface Web ont été développés pour analyser des réseaux multiplexes, que nous appelons «Visual Cloud» et «Laputa». Dans le Visual Cloud, nous définissons formellement une notion de similitude entre les concepts et les groupes de concepts que nous nommons possibilité de co-occurrence (CP). Conformément à cette définition, nous proposons un algorithme de classification hiérarchique. Nous regroupons les couches dans le réseau multiplexe de documents, et intégrons cette hiérarchie dans un nuage de mots interactif. Nous améliorons les algorithmes traditionnels de disposition de mise en forme de nuages de mots de sorte à préserver les contraintes sur la hiérarchie de concepts. Le système Laputa est destiné à l’analyse complexe de réseaux temporels denses et multidimensionnels. Pour ce faire, il associe un graphe à une segmentation. La segmentation par communauté, par attribut, ou encore par tranche temporelle, forme des vues de ce graphe. Afin d’associer ces vues avec le tout global, nous utilisons des diagrammes de Sankey pour révéler l’évolution des communautés (diagrammes que nous avons augmentés avec un zoom sémantique). Cette thèse nous permet ainsi de parcourir trois aspects (3V) des plus intéressants de la donnée et du BigData appliqués aux archives multimédia: Le Volume de nos données dans l’immensité des archives, nous atteignons des ordres de grandeurs qui ne sont pas praticables pour la visualisation et l’exploitation des liens. La Vélocité à cause de la nature temporelle de nos données (par définition). La Variété qui est un corollaire de la richesse des données multimédia et de tout ce que l’on peut souhaiter vouloir y investiguer. Ce que l’on peut retenir de cette thèse c’est que la traduction de ces trois défis a pris dans tous les cas une réponse sous la forme d’une analyse de réseaux multiplexes. Nous retrouvons toujours ces structures au coeur de notre travail, que ce soit de manière plus discrète dans les critères pour filtrer les arêtes par l’algorithme Simmelian backbone, que ce soit par la superposition de tranches temporelles, ou bien que ce soit beaucoup plus directement dans la combinaison d’indices sémantiques visuels et textuels pour laquelle nous extrayons les hiérarchies permettant notre visualisation
Nowadays, information follows complex paths: information propagation involving on-line editors, 24-hour news providers and social medias following entangled paths acting on information content and perception. This thesis studies the adaptation of classical graph measurements to multiplex graphs, to build visualizations from several graphical representations of the networks, and to combine them (synchronized multi-view visualizations, hybrid representations, etc.). Emphasis is placed on the modes of interaction allowing to take in hand the multiplex nature (multilayer) of the networks. These representations and interactive manipulations are also based on the calculation of indicators specific to multiplex networks. The work is based on two main datasets: one is a 12-year archive of the Japanese public daily broadcast NHK News 7, from 2001 to 2013. Another lists the participants in the French TV/radio shows between 2010 and 2015. Two visualization systems based on a Web interface have been developed for multiplex network analysis, which we call "Visual Cloud" and "Laputa". In the Visual Cloud, we formally define a notion of similarity between concepts and groups of concepts that we call co-occurrence possibility (CP). According to this definition, we propose a hierarchical classification algorithm. We aggregate the layers in a multiplex network of documents, and integrate that hierarchy into an interactive word cloud. Here we improve the traditional word cloud layout algorithms so as to preserve the constraints on the concept hierarchy. The Laputa system is intended for the complex analysis of dense and multidimensional temporal networks. To do this, it associates a graph with a segmentation. The segmentation by communities, by attributes, or by time slices, forms views of this graph. In order to associate these views with the global whole, we use Sankey diagrams to reveal the evolution of the communities (diagrams that we have increased with a semantic zoom). This thesis allows us to browse three aspects of the most interesting aspects of the data miming and BigData applied to multimedia archives: The Volume since our archives are immense and reach orders of magnitude that are usually not practicable for the visualization; Velocity, because of the temporal nature of our data (by definition). The Variety that is a corollary of the richness of multimedia data and of all that one may wish to want to investigate. What we can retain from this thesis is that we met each of these three challenges by taking an answer in the form of a multiplex network analysis. These structures are always at the heart of our work, whether in the criteria for filtering edges using the Simmelian backbone algorithm, or in the superposition of time slices in the complex networks, or much more directly in the combinations of visual and textual semantic indices for which we extract hierarchies allowing our visualization

APA, Harvard, Vancouver, ISO, and other styles

4

Tawfik, Israa. "Links and graphs." Thesis, University of Plymouth, 2013. http://hdl.handle.net/10026.1/2863.

Full text

Abstract:

In this thesis we derive some basic properties of graphs G embedded in a surface determining a link diagram D(G), having a specified number μ(D(G)) of components. ( The relationship between the graph and the link diagram comes from the tangle which replaces each edge of the graph). Firstly, we prove that μ (D(G)) ≤ f (G) + 2g, where f (G) is the number of faces in the embedding of G and g is the genus of the surface. Then we focus on the extremal case, where μ (D(G)) = f (G) + 2g. We note that μ (D(G)) does not change when undergoing graph Reidemeister moves or embedded ∆ ↔ Y exchanges. It is also useful that μ(D(G)) changes only very slightly when an edge is added to the graph. We finish with some observations on other possible values of μ(D(G)). We comment on two cases: when μ = 1, and the Petersen and Heawood families of graphs. These two families are obtained from K6 and K7 respectively by using ∆ ↔ Y exchanges.

APA, Harvard, Vancouver, ISO, and other styles

5

Wu, Diing-Wuu Vale. "Introduction to fractal by using interactive media design /." Online version of thesis, 1991. http://hdl.handle.net/1850/11287.

Full text

APA, Harvard, Vancouver, ISO, and other styles

6

Monterio, Carlos Eduardo Ferreira. "Investigating critical sense in the interpretation of media graphs." Thesis, University of Warwick, 2005. http://wrap.warwick.ac.uk/73122/.

Full text

Abstract:

This research explores elements and processes involved in interpretation of media graphs. The investigation was comprised of a literature review and a collection of empirical data. The literature review revealed a lack of qualitative evidence related to the complex relationships between elements and processes which comprise the interpretation of media graphs. This study explores the interpretation of media graphs by primary student teachers who would be involved in teaching about graphing. The main study was composed of two complementary datasets: questionnaires and interviews, which allowed an interplay between qualitative and quantitative data. 218 undergraduate and PGCE student teachers from Britain and Brazil responded to a questionnaire with items related to individual details, reading background and media graph tasks. 13 volunteers gave interviews which explored three types of questions: reading the data, reading between the data and reading beyond the data. The interviews also recalled the questionnaire responses. The data analysis of the questionnaires was software based, and a micro analysis approach was developed with the data from the interviews. The analyses of data gave evidence for the discussion about the notion of critical sense in graphing. It was concluded that critical sense in interpretation of media graphs is related to the mobilisation and balance of several aspects, such as: mathematical knowledge, contextual reference, personal experience and affective exhibition. The discussion of the results might help the reflection about teaching and learning of graphing in ways that will support the development of critical sense.

APA, Harvard, Vancouver, ISO, and other styles

7

Ferrer, Sumsi Miquel. "Theory and Algorithms on the Median Graph. Application to Graph-based Classification and Clustering." Doctoral thesis, Universitat Autònoma de Barcelona, 2008. http://hdl.handle.net/10803/5788.

Full text

Abstract:

Donat un conjunt d'objectes, el concepte genèric de mediana està deﬁnit com l'objecte amb la suma de distàncies a tot el conjunt, més petita. Sovint, aquest concepte és usat per a obtenir el representant del conjunt.
En el reconeixement estructural de patrons, els grafs han estat usats normalment per a representar objectes complexos. En el domini dels grafs, el concepte de mediana és conegut com median graph. Potencialment, té les mateixes aplicacions que el concepte de mediana per poder ser usat com a representant d'un conjunt de grafs.
Tot i la seva simple deﬁnició i les potencials aplicacions, s'ha demostrat que el seu càlcul és una tasca extremadament complexa. Tots els algorismes existents només han estat capaços de treballar amb conjunts petits de grafs, i per tant, la seva aplicació ha estat limitada en molts casos a usar dades sintètiques sense signiﬁcat real. Així, tot i el seu potencial, ha restat com un concepte eminentment teòric.
L'objectiu principal d'aquesta tesi doctoral és el d'investigar a fons la teoria i l'algorísmica relacionada amb el concepte de medinan graph, amb l'objectiu ﬁnal d'extendre la seva aplicabilitat i lliurar tot el seu potencial al món de les aplicacions reals. Per això, presentem nous resultats teòrics i també nous algorismes per al seu càlcul. Des d'un punt de vista teòric aquesta tesi fa dues aportacions fonamentals. Per una banda, s'introdueix el nou concepte d'spectral median graph. Per altra banda es mostra que certes de les propietats teòriques del median graph poden ser millorades sota determinades condicions. Més enllà de les aportacioncs teòriques, proposem cinc noves alternatives per al seu càlcul. La primera d'elles és una conseqüència directa del concepte d'spectral median graph. Després, basats en les millores de les propietats teòriques, presentem dues alternatives més per a la seva obtenció. Finalment, s'introdueix una nova tècnica per al càlcul del median basat en el mapeig de grafs en espais de vectors, i es proposen dos nous algorismes més.
L'avaluació experimental dels mètodes proposats utilitzant una base de dades semi-artiﬁcial (símbols gràﬁcs) i dues amb dades reals (mollècules i pàgines web), mostra que aquests mètodes són molt més eﬁcients que els existents. A més, per primera vegada, hem demostrat que el median graph pot ser un bon representant d'un conjunt d'objectes utilitzant grans quantitats de dades. Hem dut a terme experiments de classiﬁcació i clustering que validen aquesta hipòtesi i permeten preveure una pròspera aplicació del median graph a un bon nombre d'algorismes d'aprenentatge.
Given a set of objects, the generic concept of median is deﬁned as the object with the smallest sum of distances to all the objects in the set. It has been often used as a good alternative to obtain a representative of the set.
In structural pattern recognition, graphs are normally used to represent structured objects. In the graph domain, the concept analogous to the median is known as the median graph. By extension, it has the same potential applications as the generic median in order to be used as the representative of a set of graphs.
Despite its simple deﬁnition and potential applications, its computation has been shown as an extremely complex task. All the existing algorithms can only deal with small sets of graphs, and its application has been constrained in most cases to the use of synthetic data with no real meaning. Thus, it has mainly remained in the box of the theoretical concepts.
The main objective of this work is to further investigate both the theory and the algorithmic underlying the concept of the median graph with the ﬁnal objective to extend its applicability and bring all its potential to the world of real applications. To this end, new theory and new algorithms for its computation are reported. From a theoretical point of view, this thesis makes two main contributions. On one hand, the new concept of spectral median graph. On the other hand, we show that some of the existing theoretical properties of the median graph can be improved under some speciﬁc conditions. In addition to these theoretical contributions, we propose ﬁve new ways to compute the median graph. One of them is a direct consequence of the spectral median graph concept. In addition, we provide two new algorithms based on the new theoretical properties. Finally, we present a novel technique for the median graph computation based on graph embedding into vector spaces. With this technique two more new algorithms are presented.
The experimental evaluation of the proposed methods on one semi-artiﬁcial and two real-world datasets, representing graphical symbols, molecules and webpages, shows that these methods are much more ecient than the existing ones. In addition, we have been able to proof for the ﬁrst time that the median graph can be a good representative of a class in large datasets. We have performed some classiﬁcation and clustering experiments that validate this hypothesis and permit to foresee a successful application of the median graph to a variety of machine learning algorithms.

APA, Harvard, Vancouver, ISO, and other styles

8

Yang, Mengta. "Depth Functions, Multidimensional Medians and Tests of Uniformity on Proximity Graphs." Thesis, The George Washington University, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=3615104.

Full text

Abstract:

We represent the d-dimensional random vectors as vertices of a complete weighted graph and propose depth functions that are applicable to distributions in d-dimensional spaces and data on graphs. We explore the proximity graphs, examine their connection to existing depth functions, define a family of depth functions on the β-skeleton graph, suggest four types of depth functions on the minimal spanning tree (MST) and define depth functions including path depth, path depth of path length at most δ, all paths probability depth, eccentricity depth, peeling depth and RUNT depth. We study their properties, including affine invariance, maximality at the center, monotonicity and vanishing at infinity. We show that the β-skeleton depth is a family of statistical depth functions and define the sample β-skeleton depth function. We show that it has desirable asymptotic properties, including uniform consistency and asymptotic normality. We consider the corresponding multidimensional medians, investigate their robustness, computational complexity, compare them in a simulation study to find the multivariate medians under different distributions and sample sizes and explore the asymptotic properties of β-skeleton median. We generalize the univariate Greenwood statistic and Hegazy-Green statistic using depth induced order statistics and propose two new test statistics based on normal copula and interpoint distances for testing multivariate uniformity. We generalize the path depth under two-sample setting and propose a new multivariate equality of DF test. We study their empirical power against several copula and multivariate Beta alternatives. The topic is complemented with a discussion on the distribution and moments of the interpoint distances (ID) between bivariate uniform random vectors and the IDs between FGM copula random vectors.

APA, Harvard, Vancouver, ISO, and other styles

9

Ratel, Sébastien. "Densité, VC-dimension et étiquetages de graphes." Electronic Thesis or Diss., Aix-Marseille, 2019. http://www.theses.fr/2019AIXM0427.

Full text

Abstract:

Une partie des résultats de cette thèse sont initialement motivés par l'élaboration de schémas d'étiquetage permettant de réponde à l'adjacence, à la distance ou au routage. Ce document traite cependant de problèmes d'intérêt plus généraux tels que l'étude de bornes sur la densité de graphes, de la VC-dimension de familles d'ensembles, ou de propriétés métriques et structurelles.Nous établissons dans un premier temps des bornes supérieures sur la densité des sous-graphes de produits cartésien de graphes, puis des sous-graphes de demi-cubes. Pour ce faire, nous définissons des extensions du paramètre classique de VC-dimension. De ces bornes sur la densité, nous déduisons des bornes supérieures sur la longueur des étiquettes attribuées par un schéma d'adjacence à ces deux familles de graphes.Dans un second temps, nous nous intéressons à des schémas de distance et de routage pour deux familles importantes de la théorie métrique des graphes: les graphes médians et les graphes pontés. Nous montrons que la famille des graphes médians, sans cube, avec n sommets, admet des schémas de distance et de routage utilisant des étiquettes de O(\log^3 n). Ces étiquettes sont décodées en temps constant pour calculer, respectivement, la distance exacte entre deux sommets, ou le port vers un sommet rapprochant une source d'une destination. Nous décrivons ensuite un schéma de distances 4-approchées pour la famille des graphes pontés, sans K_4, avec n sommets, utilisant des étiquettes de O(\log^3 n) bits. Ces dernières peuvent être décodées en temps constant pour obtenir une valeur entre la distance exacte et quatre fois celle-ci
Constructing labeling schemes supporting adjacency, distance or routing queries constituted the initial motivation of most of the results of this document. However, this manuscript concerns problem of more general interest such as bounding the density of graphs, studying the VC-dimension of set families, or investigating on metric and structural properties of graphs. As a first contribution, we upper bound the density of the subgraphs of Cartesian products of graphs, and of the subgraphs of halved-cubes. To do so, we extend the classical notion of VC-dimension (already used in 1994 by Haussler, Littlestone, and Warmuth to upper bound the density of the subgraphs of hypercubes). From our results, we deduce upper bounds on the size of labels used by an adjacency labeling scheme on these graph classes. We then investigate on distance and routing labeling schemes for two important families of metric graph theory: median graphs and bridged graphs. We first show that the class of cube-free median graphs on n vertices enjoys distance and routing labeling schemes both using labels of O(\log^3 n) bits. These labels can be decoded in constant time to respectively return the exact distance between two vertices, or a port to take from a source vertex in order to get (strictly) closer to a target one. We then describe an approximate distance labeling scheme for the family of K_4-free bridged graphs on n vertices. This scheme also uses labels of size O(\log^3 n) that can be decoded in constant time to return a value of at most four time the exact distance between two vertices

APA, Harvard, Vancouver, ISO, and other styles

10

Johansson, Erik. "Phos Graphis." Thesis, Blekinge Tekniska Högskola, Sektionen för teknokultur, humaniora och samhällsbyggnad, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-1627.

Full text

Abstract:

Phos Graphis är en mötesplats för fotografer och modeller. Denna mötesplats ska fungera som en grund för att hitta den medpart man söker, t.ex. en fotograf som letar efter en modell till ett projekt. Användarna erbjuds även egna gallerier och möjligheter att diskutera i forum samt privat meddelandefunktionalitet. Grundtanken är att Phos Graphis ska fungera som ett verktyg för att lättare kunna utvecklas inom sin roll.

APA, Harvard, Vancouver, ISO, and other styles

11

Ribeiro, Andre Figueiredo. "Graph dynamics : learning and representation." Thesis, Massachusetts Institute of Technology, 2006. http://hdl.handle.net/1721.1/34184.

Full text

Abstract:

Thesis (S.M.)--Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2006.
Includes bibliographical references (p. 58-60).
Graphs are often used in artificial intelligence as means for symbolic knowledge representation. A graph is nothing more than a collection of symbols connected to each other in some fashion. For example, in computer vision a graph with five nodes and some edges can represent a table - where nodes correspond to particular shape descriptors for legs and a top, and edges to particular spatial relations. As a framework for representation, graphs invite us to simplify and view the world as objects of pure structure whose properties are fixed in time, while the phenomena they are supposed to model are actually often changing. A node alone cannot represent a table leg, for example, because a table leg is not one structure (it can have many different shapes, colors, or it can be seen in many different settings, lighting conditions, etc.) Theories of knowledge representation have in general concentrated on the stability of symbols - on the fact that people often use properties that remain unchanged across different contexts to represent an object (in vision, these properties are called invariants). However, on closer inspection, objects are variable as well as stable. How are we to understand such problems? How is that assembling a large collection of changing components into a system results in something that is an altogether stable collection of parts?
(cont.) The work here presents one approach that we came to encompass by the phrase "graph dynamics". Roughly speaking, dynamical systems are systems with states that evolve over time according to some lawful "motion". In graph dynamics, states are graphical structures, corresponding to different hypothesis for representation, and motion is the correction or repair of an antecedent structure. The adapted structure is an end product on a path of test and repair. In this way, a graph is not an exact record of the environment but a malleable construct that is gradually tightened to fit the form it is to reproduce. In particular, we explore the concept of attractors for the graph dynamical system. In dynamical systems theory, attractor states are states into which the system settles with the passage of time, and in graph dynamics they correspond to graphical states with many repairs (states that can cope with many different contingencies). In parallel with introducing the basic mathematical framework for graph dynamics, we define a game for its control, its attractor states and a method to find the attractors. From these insights, we work out two new algorithms, one for Bayesian network discovery and one for active learning, which in combination we use to undertake the object recognition problem in computer vision. To conclude, we report competitive results in standard and custom-made object recognition datasets.
by Andre Figueiredo Ribeiro.
S.M.

APA, Harvard, Vancouver, ISO, and other styles

12

Zhu, Yanshu, and 朱妍姝. "Compact representation of medial axis transform." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2014. http://hdl.handle.net/10722/206472.

Full text

Abstract:

Shape representation is a fundamental topic in geometric modeling, which is ubiquitous in computer graphics. Compared with the explicit and implicit shape representations, the medial representation possesses many advantages. It provides a comprehensive understanding of the shapes, since it gives direct access to both the boundaries and the interiors of the shapes. Although there are many medial axis computation algorithms which are able to filter noises in the medial axis, introduced by the perturbations on the boundary, and generate stable medial axis transforms of the input shapes, the medial axis transforms are usually represented in a redundant way with numerous primitives, which brings down the flexibility of the medial axis transform and hinders the popularity of the medial axis transform in geometric applications. In this thesis, we propose compact representations of the medial axis transforms for 2D and 3D shapes. The first part of this thesis proposes a full pipeline for computing the medial axis transform of an arbitrary 2D shape. The instability of the medial axis transform is overcome by a pruning algorithm guided by a user-defined Hausdorff distance threshold. The stable medial axis transform is then approximated by spline curves in the 3D space to produce a smooth and compact representation. These spline curves are computed by minimizing the approximation error between the input shape and the shape represented by the medial axis transform. The second part of this thesis discusses improvements on the existing medial axis computation algorithms, and represent the medial axis transform of a 3D shape in a compact way. The CVT remeshing framework is applied on an initial medial axis transform to promote the mesh quality of the medial axis. The simplified medial axis transform is then optimized by minimizing the approximation error of the shape reconstructed from the medial axis transform to the original 3D shape. Our results on various 2D and 3D shapes suggest that our method is practical and effective, and yields faithful and compact representations of medial axis transforms of 2D and 3D shapes.
published_or_final_version
Computer Science
Doctoral
Doctor of Philosophy

APA, Harvard, Vancouver, ISO, and other styles

13

Rizzo, Thomas Philip. "Capacitated, unbalanced p-median problems on a chain graph with a continuum of link demands." Thesis, Virginia Polytechnic Institute and State University, 1986. http://hdl.handle.net/10919/91146.

Full text

Abstract:

This study is concerned with the problem of locating p capacitated facilities on a chain graph, and simultaneously determining the allocation of their supplies in order to satisfy a continuum of demand which is characterized by some weighted probability density function defined on the chain graph. The objective is to minimize the total (expected) transportation cost. This location-allocation problem is also referred to as the capacitated p-median problem on a chain graph. Two unbalanced cases of this problem are considered, namely, the over-capacitated case when total supply exceeds total demand, and the deficit capacity case when total supply is less than total demand. Both these problems are nonconvex, and are shown to be NP-hard even if the demand density function is piecewise uniform and positive. We provide a first-order characterization of optimality for these two problems, and prescribe an enumerative algorithm based on a partitioning of the dual space in order to optimally solve them. An extension of these algorithms for solving the capacitated, unbalanced 2-median problem on a tree graph is also given.
M.S.

APA, Harvard, Vancouver, ISO, and other styles

14

Costa, André Luis da 1982. "Corte normalizado em grafos = um algoritmo aglomerativo para segmentação de imagens de colonias de bactérias= Normalized cut on graphs: an aglomerative algorithm for bacterial colonies image segmentation." [s.n.], 2013. http://repositorio.unicamp.br/jspui/handle/REPOSIP/267753.

Full text

Abstract:

Orientador: Marco Antonio Garcia de Carvalho
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Tecnologia
Made available in DSpace on 2018-08-22T22:09:46Z (GMT). No. of bitstreams: 1 Costa_AndreLuisda_M.pdf: 6614237 bytes, checksum: b36b41dce03cbb78f037ec20725bddd2 (MD5) Previous issue date: 2013
Resumo: O problema de segmentação de colônias de bactérias em placas de Petri possui algumas características bem distintas daquelas encontradas, por exemplo, em problemas de segmentação de imagens naturais. A principal característica é o alto número de colônias que podem ser encontradas em uma placa. Desta forma, é primordial que o algoritmo de segmentação seja capaz de realizar a segmentação da imagem em um grande número de regiões. Este cenário extremo é ideal para analisar limitações dos algoritmos de segmentação. De fato, neste trabalho foi verificado que o algoritmo de corte normalizado original, que se fundamenta na teoria espectral de grafos, é inadequado para aplicações que exigem que a segmentação seja realizada em um grande número de regiões. Contudo, a utilização do critério de corte normalizado para segmentar imagens de colônias de bactérias ainda é possível graças a um novo algoritmo que está sendo introduzido neste trabalho. O novo algoritmo fundamenta-se no agrupamento hierárquico dos nós do grafo, ao invés de utilizar conceito da teoria espectral. Experimentos mostram também que o biparticionamento de um grafo pelo novo algoritmo apresenta um valor de corte normalizado médio cerca de 40 vezes menor que o biparticionamento pelo algoritmo baseado na teoria espectral
Abstract: The problem of bacteria colonies segmentation in Petri dishes has some very different characteristics from those found, for example, in segmenting natural images. The main feature is the high number of colonies that can be found on a plate. Thus, it is essential that the segmentation algorithm is capable of performing the image segmentation into a huge number of regions. This extreme scenario is ideal for analyzing segmentation algorithms limitations. In fact, this study showed that the original normalized cut algorithm, which is based on the spectral graph theory, is inappropriate for applications that require that the segmentation be performed on a large number of regions. However, the use of normalized cut criteria for segmenting bacteria colonies images is still possible thanks to a new algorithm that is being introduced in this paper. The new algorithm is based on hierarchical clustering of the graph nodes, instead of using the spectral theory concepts. Experiments also show that the bi-partitioning of a graph by the new algorithm has a normalized cut average value about 40 times lesser than the bi-partitioning by the algorithm based on the spectral theory
Mestrado
Tecnologia e Inovação
Mestre em Tecnologia

APA, Harvard, Vancouver, ISO, and other styles

15

Zulfiqar, Omer. "Detecting Public Transit Service Disruptions Using Social Media Mining and Graph Convolution." Thesis, Virginia Tech, 2021. http://hdl.handle.net/10919/103745.

Full text

Abstract:

In recent years we have seen an increase in the number of public transit service disruptions due to aging infrastructure, system failures and the regular need for maintenance. With the fleeting growth in the usage of these transit networks there has been an increase in the need for the timely detection of such disruptions. Any types of disruptions in these transit networks can lead to delays which can have major implications on the daily passengers. Most current disruption detection systems either do not operate in real-time or lack transit network coverage. The theme of this thesis was to leverage Twitter data to help in earlier detection of service disruptions. This work involves developing a pure Data Mining approach and a couple different approaches that use Graph Neural Networks to identify transit disruption related information in Tweets from a live Twitter stream related to the Washington Metropolitan Area Transit Authority (WMATA) metro system. After developing three different models, a Dynamic Query Expansion model, a Tweet-GCN and a Tweet-Level GCN to represent the data corpus we performed various experiments and benchmark evaluations against other existing baseline models, to justify the efficacy of our approaches. After seeing astounding results across both the Tweet-GCN and Tweet-Level GCN, with an average accuracy of approximately 87.3% and 89.9% we can conclude that not only are these two graph neural models superior for basic NLP text classification, but they also outperform other models in identifying transit disruptions.
Master of Science
Millions of people worldwide rely on public transit networks for their daily commutes and day to day movements. With the growth in the number of people using the service, there has been an increase in the number of daily passengers affected by service disruptions. This thesis and research involves proposing and developing three different approaches to help aid in the timely detection of these disruptions. In this work we have developed a pure data mining approach along with two deep learning models using neural networks and live data from Twitter to identify these disruptions. The data mining approach uses a set of dirsuption related input keywords to identify similar keywords within the live Twitter data. By collecting historical data we were able to create deep learning models that represent the vocabulary from the disruptions related Tweets in the form of a graph. A graph is a collection of data values where the data points are connected to one another based on their relationships. A longer chain of connection between two words defines a weak relationship, a shorter chain defines a stronger relationship. In our graph, words with similar contextual meanings are connected to each other over shorter distances, compared to words with different meanings. At the end we use a neural network as a classifier to scan this graph to learn the semantic relationships within our data. Afterwards, this learned information can be used to accurately classify the disruption related Tweets within a pool of random Tweets. Once all the proposed approaches have been developed, a benchmark evaluation is performed against other existing text classification techniques, to justify the effectiveness of the approaches. The final results indicate that the proposed graph based models achieved a higher accuracy, compared to the data mining model, and also outperformed all the other baseline models. Our Tweet-Level GCN had the highest accuracy of 89.9%.

APA, Harvard, Vancouver, ISO, and other styles

16

He, Shuiqing, and 何水清. "Spectral analysis of medial axis for shape description." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2015. http://hdl.handle.net/10722/212606.

Full text

Abstract:

In this thesis, we make several significant achievements towards defining a medial axis based shape descriptor which is compact, yet discriminative. First, we propose a novel medial axis spectral shape descriptor called the medial axis spectrum for a 2D shape, which applies spectral analysis directly to the medial axis of a 2D shape. We extend the Laplace-Beltrami operator onto the medial axis of a 2D shape, and take the solution to an extended Laplacian eigenvalue problem defined on this axis as the medial axis spectrum. The medial axis spectrum of a 2D shape is certainly more efficient to compute than spectral analysis of a 2D region, since the efficiency of solving the Laplace eigenvalue problem strongly depends on the domain dimension. We show that the medial axis spectrum is invariant under uniform scaling and isometry of the medial axis. It could also overcome the medial axis noise problem automatically, due to the incorporation of the hyperbolic distance metric. We also demonstrate that the medial axis spectrum inherits several advantages in terms of discriminating power over existing methods. Second, we further generalize the medial axis spectrum to the description of medial axes of 3D shapes, which we call the medial axis spectrum for a 3D shape. We develop a newly defined Minkowski-Euclidean area ratio inspired by the Minkowski inner product to characterize the geometry of the medial axis surface of a 3D mesh. We then generalize the Laplace-Beltrami operator to the medial axis surface, and take the solution to an extended Laplacian eigenvalue problem defined on the surface as the medial axis spectrum. As the 2D case, the medial axis spectrum of a 3D shape is invariant under rigid transformation and isometry of the medial axis, and is robust to shape boundary noise as shown by our experiments. The medial axis spectrum is finally used for 3D shape retrieval, and its superiority over previous work is shown by extensive comparisons.
published_or_final_version
Computer Science
Doctoral
Doctor of Philosophy

APA, Harvard, Vancouver, ISO, and other styles

17

Bruno, Alexander. "Visual-Audio Media: Transformation and Communication." VCU Scholars Compass, 2015. http://scholarscompass.vcu.edu/etd/3768.

Full text

Abstract:

Designers are often concerned with communication through the visual; we focus on the printed object, images on screens, furniture, spaces, and other visual experiences. We should also be cognizant of audio and its communicative properties, especially when contextualized with visual content. Pairing visuals and audio can make a greater impact upon a viewer/listener than each media might make alone. My research focuses on a practice of working within strict sets of rules and boundaries to create visual-audio work. This visual-audio work not only communicates a concept or idea, but also lives as a research artifact of my design processes.

APA, Harvard, Vancouver, ISO, and other styles

18

Rajeh, Tawfik. "Modeling flow in fractured geologic media : upscaling and application to deep geothermal reservoirs." Thesis, Toulouse, INPT, 2019. http://www.theses.fr/2019INPT0051.

Full text

Abstract:

Fractures dans les roches constituent un chemin préférentiel pour les écoulements et les transferts dans les milieux géologiques. Les roches poreuses fracturées se retrouvent dans diverses applications comme par exemple l’ingénierie pétrolière et gazière, le stockage géologique du CO2 et l’extraction d’énergie géothermique. Cette thèse de doctorat présente un ensemble d’analyses des propriétés géométriques, topologiques et hydrauliques des réseaux de fractures dans une perspective d’homogénéisation et d’application à la simulation numérique des réservoirs géothermique. La description des fractures planes en 3D, ou plus spécifiquement des réseaux de fractures discrets (dénommés « DFN » pour « Discrete Fracture Networks »), leurs propriétés statistiques et la façon de les modéliser sont étudiés. Comme la perméabilité joue un rôle essentiel dans l’écoulement et le transport dans les roches poreuses fracturées, nous avons dans un premier temps développé une procédure de changement d’échelle (upscaling) pour déterminer le tenseur de perméabilité équivalente des milieux poreux fracturé en 3D. Cette nouvelle approche est basée sur le principe de superposition, amélioré par des facteurs de connectivité déterminés tout d’abord empiriquement. Ces facteurs correctifs ont pour but de prendre en compte les propriétés de connectivité et de percolation des réseaux de fractures. Malgré son efficacité à prédire la perméabilité équivalente, la méthode proposée présente deux limitations dues essentiellement à la difficulté numérique de capter la percolation et les détails des connections des réseaux de fractures. Pour surmonter ces difficultés et pour effectuer des analyses plus fines des réseaux de fractures, un nouvel outil d’analyse des propriétés géométriques et topologiques des réseaux de fractures 3D a été développé. Dans cet outil, tous les attributs géométriques et topologiques (calcul d’intersections, longueurs de traces, amas percolant, etc.) des réseaux de fractures sont déterminés par un ensemble d’algorithmes. Ces algorithmes sont validés en détails, et leurs efficacités computationnelles sont démontrées. La finalité de ces outils algorithmiques est de donner une représentation des réseaux de fractures par graphes. Avec ces nouveaux outils, les capacités à traiter des réseaux de fractures 3D sont fortement améliorées. Ainsi, en utilisant la représentation en graphes, de nouvelles approches ont été développées concernant trois aspects des réseaux de fractures : (i) la percolation, (ii) le phénomène de groupement de fractures (Clustering) et (iii) la monté d’échelle de la perméabilité par la méthode des graphes. Un simulateur thermo-hydraulique a in fine été développé avec le code open source « OpenFoam ». L’objectif est d’appliquer les techniques de changement d’échelle développées dans cette thèse à des problèmes de simulations des réservoirs géothermiques. Un premier exemple prototype de système de deux puits d’injection-production dans un réservoir géothermique est simulé. D’autres cas sont en cours de traitement dans le cadre du projet GEOTREF ( www.geotref.com )
Fractures constitute major pathways for flow and transport in fractured porous rocks. These types of rocks are encountered in a wide range of applications like for example gas and petroleum engineering, CO2 sequestration and geothermal energy extraction. The present thesis presents a framework to analyze geometrical, topological and hydraulic properties of 3D planar fracture networks with focus on upscaling these properties to obtain an equivalent continuum, in view of application to simulations of geothermal reservoir exploitation. The description of fractures and discrete fracture networks (DFN), their statistical properties and their generation procedures are studied. As permeability plays a key role in flow and transport in fractured porous rocks, we have developed a fast upscaling approach for determining the equivalent permeability tensor of 3D fractured porous media. This new approach is based on the superposition principle improved by empirical connectivity factors in order to take into account the connectivity and percolation properties of the fracture network. Although efficient in predicting permeability, the proposed method presents a major limitation due mainly to the difficulty in assessing the percolation and connectivity properties of the network. To overcome these limitations and for further insightful analyses of DFN composed of planar fractures, an original framework of geometrical and topological analysis of 3D fracture networks has been developed. In this framework, all the geometrical and topological attributes (intersections, areas, trace lengths, clusters, percolating clusters, etc.) of a DFN are explicitly calculated by a set of algorithms. These algorithms are validated in detail by comparison to commercial softwares, and their computational efficiency is highlighted. The final purpose of this framework is to give a graph representation of the DFN. Given the newly developed tools, our capabilities of treating fracture networks have drastically increased. Hence, using a graph representation of the DFN, new approaches have been developed concerning two main issues with fracture networks: (i) percolation, (ii) clustering phenomenon (i.e., the formation of clusters by groups of fractures) and (iii) permeability upscaling. A large scale thermo-hydraulic simulator has therefore been developed with the finite volume open source code “OpenFoam”. The purpose is to apply the upscaling techniques to large scale reservoir configurations with a full coupling with heat transfer. A typical example of injectionproduction wells in a 3D geothermal reservoir is presented, and other cases are being developed within the GEOTREF project ( www.geotref.com )

APA, Harvard, Vancouver, ISO, and other styles

19

Yamak, Zaher Rabah. "Multiple identities detection in online social media." Thesis, Normandie, 2018. http://www.theses.fr/2018NORMIR01/document.

Full text

Abstract:

Depuis 2004, les médias sociaux en ligne ont connu une croissance considérable. Ce développement rapide a eu des effets intéressants pour augmenter la connexionet l'échange d'informations entre les utilisateurs, mais certains effets négatifs sont également apparus, dont le nombre de faux comptes grandissant jour après jour.Les sockpuppets sont les multiples faux comptes créés par un même utilisateur. Ils sont à l'origine de plusieurs types de manipulations comme la création de faux comptes pour louer, défendre ou soutenir une personne ou une organisation, ou pour manipuler l'opinion publique. Dans cette thèse, nous présentons SocksCatch, un processus complet de détection et de groupage des sockpuppets composé de trois phases principales : la première phase a pour objectif la préparation du processus et le pré-traitement des données; la seconde phase a pour objectif la détection des comptes sockpuppets à l'aide d'algorithmes d'apprentissage automatique; la troisième phase a pour objectif le regroupement des comptes sockpuppets créés par un même utilisateur à l'aide d'algorithmes de détection de communautés. Ces phases sont déclinées en trois étapes : une étape "modèle" pour représenter les médias sociaux en ligne, où nous proposons un modèle général de médias sociaux dédié à la détection et au regroupement des sockpuppets ; une étape d'adaptation pour ajuster le processus à un média social spécifique, où nous instancions et évaluons le modèle SocksCatch sur un média social sélectionné ; et une étape en temps réel pour détecter et grouper les sockpuppets en ligne, où SocksCatch est déployé en ligne sur un média social sélectionné. Des expérimentations ont été réalisées sur l'étape d'adaptation en utilisant des données réelles extraites de Wikipédia anglais. Afin de trouver le meilleur algorithme d'apprentissage automatique pour la phase de détection de sockpuppet, les résultats de six algorithmes d'apprentissage automatique sont comparés. En outre, ils sont comparés à la littérature où les résultats de la comparaison montrent que notre proposition améliore la précision de la détection des sockpuppets. De plus, les résultats de cinq algorithmes de détection de communauté sont comparés pour la phase de regroupement de Sockpuppet, afin de trouver le meilleur algorithme de détection de communauté qui sera utilisé en temps réel
Since 2004, online social medias have grown hugely. This fast development had interesting effects to increase the connection and information exchange between users, but some negative effects also appeared, including fake accounts number growing day after day. Sockpuppets are multiple fake accounts created by a same user. They are the source of several types of manipulation such as those created to praise, defend or support a person or an organization, or to manipulate public opinion. In this thesis, we present SocksCatch, a complete process to detect and group sockpuppets, which is composed of three main phases: the first phase objective is the process preparation and data pre-processing; the second phase objective is the detection of the sockpuppet accounts using machine learning algorithms; the third phase objective is the grouping of sockpuppet accounts created by a same user using community detection algorithms. These phases are declined in three stages: a model stage to represent online social medias, where we propose a general model of social media dedicated to the detection and grouping of sockpuppets; an adaptation stage to adjust the process to a particular social media, where we instantiate and evaluate the SocksCatch model on a selected social media; and a real-time stage to detect and group the sockpuppets online, where SocksCatch is deployed online on a selected social media. Experiments have been performed on the adaptation stage using real data crawled from English Wikipedia. In order to find the best machine learning algorithm for sockpuppet's detection phase, the results of six machine learning algorithms are compared. In addition, they are compared with the literature, and the results show that our proposition improves the accuracy of the detection of sockpuppets. Furthermore, the results of five community detection algorithms are compared for sockpuppet's grouping phase, in order to find the best community detecton algorithm that will be used in real-time stage

APA, Harvard, Vancouver, ISO, and other styles

20

Ajami, Sam, and Lucas Maupin. "The effects of video gaming on university grades." Thesis, KTH, Skolan för datavetenskap och kommunikation (CSC), 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-146654.

Full text

Abstract:

I dagens IT-värld har användningen av datorspel ökat enormt och tagit en ordentlig plats i många unga människors upptagna vardag. Som ett resultat av detta har det börjat växa en oro bland många att detta spelande påverkar människorna negativt, speciellt när det gäller de akademiska prestationerna. Denna rapport är en undersökning för att finna eventuella samband mellan datorspel och högskolebetyg bland studenter. Undersökningens resultat indikerar att studenter som spelar mer, har större problem med sina betyg än de som spelar mindre. Resultaten indikerar dock också att det inte är spelandet i sig som är orsaken till problemet, eftersom korrelationen mellan antal timmar spenderat på datorspel och betyg, och korrelationen mellan antal timmar spenderat på andra hobbys och betyg, är starkt jämförbara. Detta tyder på att två timmars datorspelande påverkar betygen lika mycket som två timmar av fysisk träning. Slutsatsen av vår undersökning är att det är tiden som man spenderar på andra saker än att studera, som påverkar betygen. Däremot är datorspel bland de enklaste aktiviteterna att engagera sig i under en längre tidsperiod, och därmed också indirekt bland de mest potentiellt skadliga aktiviteterna för en students betyg.
In this 21st century IT-world, the use of video gaming has dramatically grown and taken a firm place in many young peoples’ busy day-to-day schedule. As a result, many are growing worried that video gaming will affect people in a negative way, especially when it comes to students’ academic performance. This thesis is an investigation of the correlation between games and university grades amongst students. Our results show that students, who played more, had more problems with their grades than the ones who played less. However, the results also show that gaming itself is not the problem, as the correlation between hours spent gaming and grades, is similar to the correlation between hours spent on other hobbies and grades. In essence, two hours of video gaming affects the grades just as much as two hours of physical exercise. The conclusion from our research is that it is the time spent on other activities than studying, that affects the grades. Video gaming is however amongst the easiest activities to be engaged in for an extended period of time, and can therefore be indirectly harmful to students’ grades.

APA, Harvard, Vancouver, ISO, and other styles

21

De, Santis Simone. "Quantum Median Filter for Total Variation denoising." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2022.

Find full text

Abstract:

In this work we present Quantum Median Filter, an image processing algorithm for applying Total Variation denoising to quantum image representations. After a brief introduction to TV model and quantum computing, we present QMF algorithm and discuss its design and efficiency; then we implement and simulate the quantum circuit using Qiskit library; finally we apply it to a set of noisy images, in order to compare and evaluate experimental results.

APA, Harvard, Vancouver, ISO, and other styles

22

Wang, Rui, and 王睿. "Medial axis simplification based on global geodesic slope and accumulated hyperbolic distance." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2012. http://hub.hku.hk/bib/B48330139.

Full text

Abstract:

The medial axis is an important shape representation and the computation of the medial axis is a fundamental research problem in computer graphics. Practically, the medial axis is widely used in various aspects of computer graphics, such as shape analysis, image segmentation, skeleton extraction and mesh generation and so forth. However, the applications of the medial axis have been limited by its sensitivity to boundary perturbations. This characteristic may lead to a number of noise branches and increase the complexity of the medial axis. To solve the sensitivity problem, it is critical to simplify the medial axis. This thesis first investigates the algorithms for computing medial axes of different input shapes. Several algorithms for the filtration of medial axes are then reviewed, such as the local importance measurement algorithms, boundary smoothness algorithms, and the global algorithms. Two novel algorithms for the simplification of the medial axis are proposed to generate a stable and simplified medial axis as well as its reconstructed boundary. The developed Global Geodesic Slope(GGS) algorithm for the medial axis simplification is based on the global geodesic slope defined in this thesis, which combines the advantages of the global and the local algorithms. The GGS algorithm prunes the medial axis according to local features as well as the relative size of the shape. It is less sensitive to boundary noises than the local algorithms, and can maintain the features of the shape in highly concave regions while the global algorithms may not. The other simplification algorithm we propose is the Accumulated Hyperbolic Distance(AHD) algorithm. It directly uses the evaluation criterion of the error, accumulated hyperbolic distance defined in this thesis, as the pruning measurement in the filtration process. It guarantees the upper bound of the error between the reconstructed shape and the original one within the defined threshold. The AHD algorithm avoids sudden changes of the reconstructed shape as the defined threshold changes.
published_or_final_version
Computer Science
Master
Master of Philosophy

APA, Harvard, Vancouver, ISO, and other styles

23

Khodabandeh, Bizhan. "Voice by Design: Experiments in Redistributing Media." VCU Scholars Compass, 2008. http://scholarscompass.vcu.edu/etd/980.

Full text

Abstract:

In this project I conduct two experiments in redistributing media power and reflect upon how successful they were. The experiments include a poster campaign specific to Richmond and a project dealing with educating people about guerrilla media techniques.

APA, Harvard, Vancouver, ISO, and other styles

24

Timney, Todd F. "Design History Matters: Visualizing Graphic Design History Through New Media." VCU Scholars Compass, 2007. http://scholarscompass.vcu.edu/etd_retro/38.

Full text

Abstract:

New media's emerging influence on society and the design profession is profound. Currently unrealized, the intersection of graphic design history and digital media is an area worthy of further examination. For graphic designers trained in the design of fixed content for traditional media, new media's challengeto develop open-ended systems that adapt to dynamic content, customization, and multiple authorshipcan be unsettling. But the potential benefits of this exploration are many. The ability to synthesize video, sound, static imagery, and textual information to present interactive content that adapts to the contemporary history of graphic design student's multi-modal and mobile lifestyle will provide a significant advantage.

APA, Harvard, Vancouver, ISO, and other styles

25

Vicente, Miguel Reis. "User characterization in social media." Master's thesis, Universidade de Aveiro, 2016. http://hdl.handle.net/10773/21758.

Full text

Abstract:

Mestrado em Engenharia de Computadores e Telemática
O crescimento acentuado das Redes Sociais que se verificou num passado recente, criou uma nova área de estudo na investigação em análise e extração de dados. A sua disseminação pela sociedade moderna torna-as uma fonte interessante para a aplicação de ciência dos dados, visto que auxiliam a perceção de comportamentos e padrões em dados sociais. Este tipo de informação possui valor estratégico em áreas como a publicidade e o marketing. Nesta dissertação é apresentado um protótipo para uma aplicação web que visa apresentar informação sobre a rede Twitter e os utilizadores que a compõem, através de esquemas de visualização de dados. Esta aplicação adota um modelo de dados de um grafo de propriedades, armazenado numa base de dados de grafos, para permitir uma análise eficiente das relações entre os dados existentes no Twitter. Para além disso, também faz uso de algoritmos de aprendizagem supervisionados e não-supervisionados, assim como análise estatística, para extrair padrões no conteúdo de tweets e prever atributos latentes em utilizadores do Twitter. O objetivo final é permitir a caraterização dos utilizadores Portugueses do Twitter, através da interpretação dos resultados apresentados.
The massive growth of Social Media platforms in recent years has created a new area of study for Data Mining research. Its general dissemination in modern society makes it a very interesting data science resource, as it enables the better understanding of social behavior and demographic statistics, information that has strategic value in business areas like marketing and advertising. This dissertation presents a prototype for a web application that provides a number of intuitive and interactive data visualization schemes that present information about the Twitter network and its individual users. This application leverages a property graph data model, modeled from a collection of millions of tweets from the Portuguese community and stored in a state of the art graph database, to enable an efficient analysis of the existent relationships in Twitter data. It also makes use of Supervised and Unsupervised learning algorithms, as well as statistical analysis, to extract meaningful patterns in tweets content and predict latent attributes in Twitter users. The end goal is to allow the characterization of the Portuguese users in Twitter, through the created visual representations of the achieved results.

APA, Harvard, Vancouver, ISO, and other styles

26

King, Mike. "Computer media in the visual arts, and their user interfaces." Thesis, Royal College of Art, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.293932.

Full text

APA, Harvard, Vancouver, ISO, and other styles

27

Chak, Daniel 1980. "Enhanced modeling : real-time simulation and modeling of graph based problems on interactive workbenches." Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/26915.

Full text

Abstract:

Thesis (S.M.)--Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2004.
Includes bibliographical references (p. 125-127).
This thesis presents a methodology and framework for designing systems that apply real-time simulation of computational models throughout the modeling and parameter modification stages of problem solving for graph based problems. An interactive problem solving technique is presented where the lines between problem modeling and simulation are blurred, enhancing the outcome of traditional problem solving. To demonstrate the versatility of the framework and methodology, two applications not normally thought of as graph problems - a circuit design application and an airport passenger flow application - are developed and tested. Three user studies test various parts of the framework, as well as the overall concept of real-time simulation on an interactive workbench. The first study provides quantitative support for the efficacy of the interaction technique chosen for manipulating graph structures. The second provides observational results of using the circuit design application to teach physics. The third addresses whether blurred lines of modeling and analysis enhance problem solving.
by Daniel Chak.
S.M.

APA, Harvard, Vancouver, ISO, and other styles

28

Böhlen, Boris. "Ein parametrisierbares Graph-Datenbanksystem für Entwicklungswerkzeuge /." Aachen : Shaker, 2006. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=016030096&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.

Full text

APA, Harvard, Vancouver, ISO, and other styles

29

Cascaes, Julio C?sar Silveira. "Fon?grafos e Gramofones : media??es t?cnicas em Porto Alegre (1892 ? 1927)." Pontif?cia Universidade Cat?lica do Rio Grande do Sul, 2016. http://tede2.pucrs.br/tede2/handle/tede/6628.

Full text

Abstract:

Submitted by Setor de Tratamento da Informa??o - BC/PUCRS (tede2@pucrs.br) on 2016-05-03T15:19:45Z No. of bitstreams: 1 DIS_JULIO_CESAR_SILVEIRA_CASCAES_COMPLETO.pdf: 4298468 bytes, checksum: 3968286b6e07b771fe1bba84d9ef77aa (MD5)
Made available in DSpace on 2016-05-03T15:19:45Z (GMT). No. of bitstreams: 1 DIS_JULIO_CESAR_SILVEIRA_CASCAES_COMPLETO.pdf: 4298468 bytes, checksum: 3968286b6e07b771fe1bba84d9ef77aa (MD5) Previous issue date: 2016-03-21
Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES
This paper discusses the history of mechanical sound recording devices and their subscription to the musical production chain and their development in Brazil, having printed sources, especially newspapers and magazines, as the means for analysis. Phonographs contributed for several technological innovations in the field of communication, but were also effective for the register of musical pieces. In the 20th century, Gramophones and records quickened the processes of mediation between the instances of production and the audiences, strengthening the first phonographic companies. The first phonograph arrived in Brazil in 1878 as a great technological innovation. The starting point is the premise that the press took fundamental part in the consolidation of these devices in the country. We intend to place sound reproducing devices within the context of representations of modernity, starting from the study of the urban changes taking place in Rio de Janeiro, S?o Paulo and Porto Alegre. The social environments of musical exchanges, the roles of cultural mediators and the main agents of technological interchange are examined in order to verify their contributions for the first phonographic records. Finally, the printed sources from Porto Alegre are analyzed so the emergence of phonographs and Gramophones can be featured. Taking urban growth, musical culture and the first phonographic experiences into account, this study will assemble city historians, old chroniclers, press critique, pieces of advertisement, catalogs and all sorts of printed material relevant to the mapping of the presence of phonographs and Gramophones in streets, bars and business establishments, probing, through texts and discourses, the exaltation of, the indifference towards and the reactions against the mechanical technology of sound recording.
Esta disserta??o problematiza a hist?ria dos reprodutores sonoros mec?nicos e sua inscri??o ? cadeia de produ??o musical brasileira, mediante a an?lise de fontes impressas (sobretudo por meio de jornais e revistas). Os fon?grafos apareceram junto a v?rias inova??es tecnol?gicas na ?rea da comunica??o, mas se mostraram tamb?m eficazes no registro de m?sicas. No s?culo XX, os gramofones e os discos aceleraram o processo de media??o t?cnica entre as inst?ncias de cria??o e o p?blico, determinando o fortalecimento das primeiras companhias fonogr?ficas. O primeiro fon?grafo chegou ao Brasil em 1878 como uma grande inova??o tecnol?gica. Parte-se do pressuposto de que a imprensa participou na consolida??o desses aparatos no pa?s. As not?cias e an?ncios dos peri?dicos brasileiros e das revistas ilustradas s?o utilizados na interpreta??o dos discursos de legitima??o e na constru??o de um p?blico consumidor. Busca-se contextualizar os reprodutores sonoros nas representa??es da modernidade, a partir da investiga??o das transforma??es urbanas ocorridas no Rio de Janeiro, S?o Paulo e Porto Alegre. Neste aspecto s?o verificados os espa?os de sociabilidade da m?sica, o papel dos mediadores culturais e os principais intermedi?rios da tecnologia para identificar suas contribui??es nos primeiros registros fonogr?ficos. Por fim, ser?o analisadas as fontes impressas porto-alegrenses para caracterizar a emerg?ncia de fon?grafos e gramofones na cidade. Considerando os aspectos de seu crescimento urbano, da sua cultura musical e das primeiras experi?ncias fonogr?ficas, este estudo tratar? de reunir os historiadores da cidade, os antigos cronistas, as cr?ticas jornal?sticas, os an?ncios publicit?rios, os cat?logos e demais impressos relevantes no rastreamento de fon?grafos e gramofones pelas ruas, lares e estabelecimentos comerciais, buscando, nos seus discursos, a exalta??o, a indiferen?a e as rea??es ? tecnologia mec?nica de grava??o sonora.

APA, Harvard, Vancouver, ISO, and other styles

30

Rickert, Markus. "Inhaltsbasierte Analyse und Segmentierung narrativer, audiovisueller Medien." Doctoral thesis, Universitätsbibliothek Chemnitz, 2017. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-226724.

Full text

Abstract:

Audiovisuelle Medien, insbesondere Filme und Fernsehsendungen entwickelten sich innerhalb der letzten einhundert Jahre zu bedeutenden Massenmedien. Große Bestände audiovisueller Medien werden heute in Datenbanken und Mediatheken verwaltet und professionellen Nutzern ebenso wie den privaten Konsumenten zur Verfügung gestellt. Eine besondere Herausforderung liegt in der Indexierung, Durchsuchung und Beschreibung der multimedialen Datenbestände. Die Segmentierung audiovisueller Medien, als Teilgebiet der Videoanalyse, bildet die Grundlage für verschiedene Anwendungen im Bereich Multimedia-Information-Retrieval, Content-Browsing und Video-Summarization. Insbesondere die Segmentierung in semantische Handlungsanschnitte bei narrativen Medien gestaltet sich schwierig. Sie setzt ein besonderes Verständnis der filmischen Stilelemente vorraus, die im Rahmen des Schaffensprozesses genutzt wurden, um die Handlung und Narration zu unterstützten. Die Arbeit untersucht die bekannten filmischen Stilelemente und wie sie sich im Rahmen algorithmischer Verfahren für die Analyse nutzen lassen. Es kann gezeigt werden, dass unter Verwendung eines mehrstufigen Analyse-Prozesses semantische Zusammenhänge in narrativen audiovisuellen Medien gefunden werden können, die zu einer geeigneten Sequenz-Segmentierung führen
Audiovisual media, especially movies and TV shows, developed within the last hundred years into major mass media. Today, large stocks of audiovisual media are managed in databases and media libraries. The content is provided to professional users as well as private consumers. A particular challenge lies in the indexing, searching and description of multimedia assets. The segmentation of audiovisual media as a branch of video analysis forms the basis for various applications in multimedia information retrieval, content browsing and video summarization. In particular, the segmentation into semantic meaningful scenes or sequences is difficult. It requires a special understanding of cinematic style elements that were used to support the narration during the creative process of film production. This work examines the cinematic style elements and how they can be used in the context of algorithmic methods for analysis. For this purpose, an analysis framework was developed as well as a method for sequence-segmentation of films and videos. It can be shown that semantic relationships can be found in narrative audiovisual media, which lead to an appropriate sequence segmentation, by using a multi-stage analysis process, based on visual MPEG-7 descriptors

APA, Harvard, Vancouver, ISO, and other styles

31

Kowalczyk, Brian P. "EGANWO : the graphic novel's escape to digital media /." Online version of thesis, 2009. http://hdl.handle.net/1850/11652.

Full text

APA, Harvard, Vancouver, ISO, and other styles

32

Bhattacharya, Devipsita, and Devipsita Bhattacharya. "Network Theoretic Approaches for Understanding and Analyzing Social Media Based News Article Propagation." Diss., The University of Arizona, 2016. http://hdl.handle.net/10150/620858.

Full text

Abstract:

Characteristically, propagation of news on the Internet is a rather complex scenario. Its comprehensive understanding requires a consideration of diverse facets such as audience, problem domain, channel and type of news being propagated. My dissertation focuses on the understanding of propagation of a specific type of news- news articles, on a particular subset of the Internet, the social media. While a number of studies have looked into the phenomenon of propagation in social media, fewer of these have examined the propagation of content, specifically news articles, published by news provider websites. My dissertation presents a set of network theory based methodologies to extract and analyze various implicit propagation networks formed as a result of news article sharing on Twitter. These methodologies cover aspects related to users' article sharing behavior, influence of the news provider's social media accounts, role of followers and similarities between propagation networks of news providers. Furthermore, it also includes useful inferences derived about the news article propagation phenomenon by using a population sized data sampled from Twitter over a nine-month period. It expands on the inferences from my published works and the challenges identified in the area of news article consumption and distribution on the Internet. My dissertation intends to provide important guidelines for researchers and organizations studying social media related phenomena to derive insights about customer behavior. From the perspective of online news consumption and distribution, my study has important implications for the audience's preference of news content delivery. It also facilitates news providers to gauge their performance on social media and for news editors to help develop editorial policies tailored for an online consumer base. Finally, my dissertation presents an extensive set of network based models and methodologies that can enrich the applied network science discipline.

APA, Harvard, Vancouver, ISO, and other styles

33

Ghazal, Salman. "Étude de la conjecture de Seymour sur le second voisinage." Phd thesis, Université Claude Bernard - Lyon I, 2011. http://tel.archives-ouvertes.fr/tel-00744560.

Full text

Abstract:

Soit D un digraphe simple (sans cycle orienté de longueur 2 ). En 1990, P. Seymour a conjecturé que D a un sommet v avec un second voisinage extérieur au moins aussi grand que son (premier) voisinage extérieur [1]. Cette conjecture est connue sous le nom de la conjecture du second voisinage du Seymour (SNC). Cette conjecture, si elle est vraie, impliquerait, un cas spécial plus faible (mais important) de la conjecture de Caccetta et Häggkvist [2] proposé en 1978 : tout digraphe D avec un degré extérieur minimum au moins égale à jV (D)j=k a un cycle orienté de longueur au plus k. Le cas particulier est k = 3, et le cas faible exige les deux : le degré extérieur minimum et le degré intérieur minimum de D sont au moins égaux à jV (D)j=k. La conjecture de Seymour restreinte au tournoi est connue sous le nom de conjecture de Dean [1]. En 1996, Fisher [3] a prouvé la conjecture de Dean en utilisant un argument de probabilité. En 2003, Chen, Shen et Yuster [4] ont démontré que tout digraphe a un sommet v tel que d+(v) _ d++(v) où =0.657298..... est l'unique racine de l'équation 2x3 + x2 - 1 = 0. En 2000, Havet et Thomassé [5] ont donné une preuve combinatoire de la conjecture de Dean, en utilisant un outil appelé l'ordre médian. Ils ont démontré que le dernier sommet d'un tel ordre a toujours un second voisinage extérieur au moins aussi grand que son voisinage extérieur. En 2007, Fidler et Yuster [6] ont utilisé l'ordre médian et un autre outil qui s'appelle le digraphe de dépendance afin de prouver la conjecture de Seymour pour tout digraphe D ayant un degré minimum jV (D)j 2. Ils l'ont montré pour tout tournoi où manque un autre sous-tournoi. El Sahili a conjecturé que pour tout D, il existe un completion T de D et un ordre médian de T tel que le denier sommet a un second voisinage extérieur au moins aussi grand que son voisinage extérieur (EC). Il est clair que, EC implique SNC. Cependant, EC propose une méthode afin de résoudre la SNC. En général, on oriente les non arcs de D de manière appropriée, afin d'obtenir un tournoi T et on essaie de trouver un sommet particulier (le denier sommet d'un ordre médian) avec la propriété désirée. Clairement, grâce aux résultats de [5] et [6], la EC est valable pour tournoi, et tout tournoi où manque un autre sous-tournoi. Nous allons vérifier EC pour tout digraphe D ayant un degré minimum jV (D)j 2. Alors, EC est vraie pour tout digraphe où la SNC est déjà connue d'être vraie non trivialement. Nous sommes aussi intéressés à la version pondérée de SNC et EC. En réalité, Fidler et Yuster [6] ont utilisé les digraphes de dépendance comme un outil supplémentaire et le fait que la SNC pondérée est vraie pour les tournois afin de prouver la SNC pour tout digraphe D ayant un degré minimum1 jV (D)j 2. Nous allons définir le digraphe de dépendance de façon plus générale et qui convient à n'importe quel digraphe. Nous allons utiliser le digraphe de dépendance et l'ordre médian comme des outils dans nos contributions à cette conjecture. Suivant la méthode proposée par la EC, nous démontrons la version pondérée de EC, et par conséquent la SNC, pour les classes des digraphes suivants : Digraphes où manque une étoile généralisée, soleil, étoile, ou un graphe complété. En outre, nous prouvons la EC, et par conséquent la SNC, pour digraphes où manque un peigne et digraphe où manque un graphe complet moins 2 arêtes indépendantes ou moins les arêtes d'une cycle de longueur 5. Par ailleurs, nous prouvons la EC, et par conséquent la SNC, pour les digraphes où manque n étoiles disjointes, sous certaines conditions sur les deux degrés minimum du digraphe de dépendance. Des conditions plus faible sont exigées dans le cas n = 1; 2; 3. Dans certains cas, on trouve au moins deux sommets avec la propriété désirée.

APA, Harvard, Vancouver, ISO, and other styles

34

Rickert, Markus. "Inhaltsbasierte Analyse und Segmentierung narrativer, audiovisueller Medien." Universitätsverlag Chemnitz, 2016. https://monarch.qucosa.de/id/qucosa%3A20753.

Full text

Abstract:

Audiovisuelle Medien, insbesondere Filme und Fernsehsendungen entwickelten sich innerhalb der letzten einhundert Jahre zu bedeutenden Massenmedien. Große Bestände audiovisueller Medien werden heute in Datenbanken und Mediatheken verwaltet und professionellen Nutzern ebenso wie den privaten Konsumenten zur Verfügung gestellt. Eine besondere Herausforderung liegt in der Indexierung, Durchsuchung und Beschreibung der multimedialen Datenbestände. Die Segmentierung audiovisueller Medien, als Teilgebiet der Videoanalyse, bildet die Grundlage für verschiedene Anwendungen im Bereich Multimedia-Information-Retrieval, Content-Browsing und Video-Summarization. Insbesondere die Segmentierung in semantische Handlungsanschnitte bei narrativen Medien gestaltet sich schwierig. Sie setzt ein besonderes Verständnis der filmischen Stilelemente vorraus, die im Rahmen des Schaffensprozesses genutzt wurden, um die Handlung und Narration zu unterstützten. Die Arbeit untersucht die bekannten filmischen Stilelemente und wie sie sich im Rahmen algorithmischer Verfahren für die Analyse nutzen lassen. Es kann gezeigt werden, dass unter Verwendung eines mehrstufigen Analyse-Prozesses semantische Zusammenhänge in narrativen audiovisuellen Medien gefunden werden können, die zu einer geeigneten Sequenz-Segmentierung führen.
Audiovisual media, especially movies and TV shows, developed within the last hundred years into major mass media. Today, large stocks of audiovisual media are managed in databases and media libraries. The content is provided to professional users as well as private consumers. A particular challenge lies in the indexing, searching and description of multimedia assets. The segmentation of audiovisual media as a branch of video analysis forms the basis for various applications in multimedia information retrieval, content browsing and video summarization. In particular, the segmentation into semantic meaningful scenes or sequences is difficult. It requires a special understanding of cinematic style elements that were used to support the narration during the creative process of film production. This work examines the cinematic style elements and how they can be used in the context of algorithmic methods for analysis. For this purpose, an analysis framework was developed as well as a method for sequence-segmentation of films and videos. It can be shown that semantic relationships can be found in narrative audiovisual media, which lead to an appropriate sequence segmentation, by using a multi-stage analysis process, based on visual MPEG-7 descriptors.

APA, Harvard, Vancouver, ISO, and other styles

35

Waites, Peter. "On the Boundaries of Watchmen : Paratextual Narratives across Media." Licentiate thesis, Uppsala universitet, Engelska institutionen, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-266867.

Full text

Abstract:

This dissertation is an intervention into the ongoing revisions of Gerard Genette’s concept of paratexts. Increasingly used in discussions of artifacts other than the literary novels that were Genette’s object of attention, the concept of paratexts has given rise to intense debates regarding the nature and functions of paratextual elements across media. One area of contestation is the relation of paratext to narrative. While Genette’s original paradigm complicates the possibility of a narrative paratext, I show that the liminal zones usually occupied by paratexts—what I call paratextual space—are commonly used for narrative purposes, particularly as popular narratives extend across media. In this dissertation, I analyze the different embodiments of Watchmen with a focus on such a use of paratextual spaces. I argue that studies of narratives presented in these spaces—what I refer to as paratextual narratives—will not only shed light on these narrative strategies, but also give new insights into how popular narratives extend across new media platforms. My first analytical chapter concerns the material that frames the Watchmen graphic narrative, and its roots in the media specific history and paratextual phenomenon known as lettercols. I show how this paratextual space was repurposed in the creation of Watchmen to present narrative material that worked to establish and augment the history of the storyworld and the characters presented in the graphic narrative of the Watchmen comics. I argue that the functions of these materials are influenced by the tradition established by the lettercols and the paratextual spaces in which they are situated. In my second analytical chapter I turn to the Watchmen adaptation, focusing in particular on the digital narratives framing the cinematic premiere of the film. I show how the paratextual nature of these materials occluded their narrative functions, causing them to be excluded from what is regarded the adaptation of Watchmen. I argue that the materials framing the Watchmen film are paratextual narratives that should be seen as integral parts of the Watchmen adaptation. In my conclusion I address the Watchmen prequel-series Before Watchmen and raise questions regarding how paratextual narratives function for media franchising.

APA, Harvard, Vancouver, ISO, and other styles

36

Schutte, Stacey C. "A study of strength and vasoactivity in a tissue engineered vascular media." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/28241.

Full text

Abstract:

Thesis (M. S.)--Mechanical Engineering, Georgia Institute of Technology, 2009.
Committee Chair: Nerem, Robert M.; Committee Member: Gleason, Rudolf L.; Committee Member: Taylor, W. Robert; Committee Member: Vito, Raymond P.; Committee Member: Wang, Yadong.

APA, Harvard, Vancouver, ISO, and other styles

37

Sisk, Christopher Andrew. "In Media Res." VCU Scholars Compass, 2018. https://scholarscompass.vcu.edu/etd/5444.

Full text

Abstract:

We are inundated by a constant feed of media that responds and adapts in real time to the impulses of our psyches and the dimensions of our devices. Beneath the surface, this stream of information is directed by hidden, automated controls and steered by political agendas. The transmission of information has evolved into a spiral of entropy, and the boundaries between author, content, platform, and receiver have blurred. This reductive space of responsive media is a catalyst for immense political and cultural change, causing us to question our notions of authority, truth, and reality.

APA, Harvard, Vancouver, ISO, and other styles

38

Wagner, Emmanuel Turaev Vladimir G. "Sur l'homologie de Khovanov-Rozansky des graphes et des entrelacs /." Paris, 2007. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=016808065&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.

Full text

APA, Harvard, Vancouver, ISO, and other styles

39

Lukovszki, Tamás. "New results on geometric spanners and their applications /." Paderborn : HNI, 1999. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=015378426&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.

Full text

APA, Harvard, Vancouver, ISO, and other styles

40

Uddin, Mohammed Saleh. "Representation of formal and spatial analysis in computational media : a case study of Louis I. Kahn's National Assembly complex." Thesis, University of Sheffield, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.310630.

Full text

APA, Harvard, Vancouver, ISO, and other styles

41

Randall, Robert 1948. "Access writing written segment and documentation accompanying the multi-media research project submitted on a series of four CD ROMs." Monash University, Dept. of Fine Arts, 1998. http://arrow.monash.edu.au/hdl/1959.1/7634.

Full text

APA, Harvard, Vancouver, ISO, and other styles

42

Coco, Giuseppe Antonio. "Social media evaluation for non-profit organizations : The case of Oxfam Italia." Thesis, Uppsala universitet, Medier och kommunikation, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-232708.

Full text

Abstract:

The thesis presents an evaluation of the Facebook page of the Italian non-profit organization Oxfam Italia from November 2013 to March 2014. The research’s aim is to analyze the community which follows the organization, how this community interacts with it and how the moderators of the page communicate with its followers. The research aims also to find ways to increase Oxfam Italia’s performance on Facebook. The theoretical framework focuses on non-profit marketing and its peculiarities, Social Media Marketing and notions such as engagement and brand community. The methods used in the research consist in data mining and content analysis. Data have been gathered from Facebook Insights and through the issuing of FQL queries from the Facebook Graph API. The research found out that Oxfam has more female followers than male (62% vs 36,5%), the age range of them is 25-44 years. Oxfam’s presence, in particular, is very rooted in the region of Tuscany (where its headquarter is). Facebook followers showed a very good attitude toward the organization, even though criticisms are common, and Oxfam used its social media presence mainly to update the followers concerning ongoing activities and to urge to on-line activism. The users’ favourite engagement method was “liking” photographic contents.

APA, Harvard, Vancouver, ISO, and other styles

43

Vandergriff, Elisa Leigh. "SONDER: Exploration of the Relationship between Digital Media and Graphic Design through the Creation of Print and Digital Publications." Digital Commons @ East Tennessee State University, 2018. https://dc.etsu.edu/honors/465.

Full text

Abstract:

Sonder is an exploration of the relationship between digital media and graphic design through the creation of print and digital publications. At it’s very foundation, Sonder is a travel magazine with both a physical print publication and a digital publication designed for a tablet. It includes photography, articles, poetry, and travel tips. The print and the digital versions contain the same content, but explore different methods of presentation.

APA, Harvard, Vancouver, ISO, and other styles

44

Langmajerová, Tereza. "Návrh mediální strategie společnosti Meetfactory." Master's thesis, Vysoká škola ekonomická v Praze, 2015. http://www.nusl.cz/ntk/nusl-206970.

Full text

Abstract:

The aim of this thesis is to create a media strategy for a non-profit organisation MeetFactory. The proposal is based on all steps of a media planning process - media brief, situation analysis, definition of goals and media strategy, as well as a mediaplan. The thesis gives a complete overview of the media market, respective mediatypes and creation of the media strategy. Since the thesis is based on the Google Ad Grants programme it contains detailed characteristics of the programme as well as creation of a Google search campaign.

APA, Harvard, Vancouver, ISO, and other styles

45

Neuhaus, Stefan. "Eigenschaften kleinster dominierender Mengen und Dominanzzahlen von Damengraphen /." München : Verl. Dr. Hut, 2009. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=017719424&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.

Full text

APA, Harvard, Vancouver, ISO, and other styles

46

Baumann, Annika. "Network Science – Applications in Technology, Business and Social Media." Doctoral thesis, Humboldt-Universität zu Berlin, 2018. http://dx.doi.org/10.18452/19216.

Full text

Abstract:

Netzwerke stellen einen integralen Bestandteil unseres Lebens dar. Eines der wichtigsten Kommunikations-Netzwerke ist das Internet, welches zu starken Veränderungen im Alltag geführt hat. Diese werden in Teilaspekten in der vorliegenden Dissertation untersucht. Insgesamt ist die Dissertation in drei Bereiche unterteilt, welche auf der traditionellen Perspektive der drei Dimensionen von Informationssystemen basieren. Diese Dimensionen umfassen die Technologie, das Management und die Organisation. Im Zentrum der Dissertation steht hierbei die Technologie-Dimension in dessen Rahmen die Struktur und Robustheit des Internets sowie anderer Netzwerke unter Nutzung des mathematisch-methodischen Aspekts der Graphentheorie analysiert werden. Der zweite Teilbereich der vorliegenden Arbeit wechselt die Perspektive hin zum Management. Unter Nutzung von Methoden der prädikativen Modellierung stehen das bessere Verständnis und die Möglichkeit der Vorhersage von Nutzerverhalten im E-Commerce-Kontext im Fokus. Der dritte Bereich umfasst die Organisations-Perspektive aus Sicht der Nutzer. Hierbei werden zwei spezielle Unterbereiche betrachtet. Der erste Unterbereich umfasst Webseiten Sozialer Medien und analysiert wie verschiedene Nutzergruppen diese verwenden. Der zweite Unterbereich befasst sich mit dem Einfluss der weitläufigen Verbreitung von mobilen Endgeräten auf Aspekte des persönlichen und beruflichen Lebens von Individuen. Aufbauend auf diesen drei Dimensionen wurden im Rahmen dieser Dissertation insgesamt 18 Studien durchgeführt, die sich unterschiedlicher methodischer Anwendungen bedienen um wissenschaftliche Erkenntnisse zu den vorgestellten Teilbereichen zu erlangen.
Networks constitute an integral part of our lives. One of the most important communication networks is the Internet which led to large changes in everyday life, which are examined in part in this dissertation. Overall, the present dissertation is subdivided into three areas, which are based on the traditional three dimensions of information systems, comprising perspectives technology, management and organization. At the core of this dissertation is the technological perspective, centered on an analysis of the structure and robustness of the Internet network using the mathematical-methodical aspect of graph theory. The second part of the thesis deals with the management perspective. The focus lies on the understanding and prediction of user behavior in the e-commerce context utilizing methods of predictive modeling. The third area includes the organizational perspective from the point of view of users. Here, two specific sub-areas are selected. The first sub-area revolves around social media websites, with the goal of understanding how sub-groups of users utilize them in different ways. The second area is centered around the aspect of how the propagation of mobile devices influences individuals in their personal and professional environments. Based on these three perspectives, a total of 18 studies were conducted within the scope of this dissertation, using different methodological applications to gain scientific insights with respect to the areas examined.

APA, Harvard, Vancouver, ISO, and other styles

47

Helgesson, Joy. "English in the digital era : Swedish grades 4-6 teachers’ use of pupil’s extramural English experience of new media." Thesis, Högskolan Dalarna, Pedagogiskt arbete, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:du-27445.

Full text

Abstract:

Technology advances at a fast rate and pupils encounter a larger amount of English outside school than they do in the EFL classroom. In addition, an update to the Swedish curriculum (LGR 11), that concerns digitalization takes effect in July this year (2018). That is why this thesis aims to explore Swedish EFL teachers’ use of pupils’ extramural (out-of-school) English experience of new media in the EFL classroom. New media is a means of mass communication, a product or service that provides entertainment or information through a computer or the Internet. New media is generally created by the users and for this thesis, relevant new media are social media, social networks sites, online streaming, fan sites and gaming. The results of this study show that about two-thirds of the 27 teachers surveyed in this study have used new media in their English teaching sometime in the last two years. Most of the teachers use it because they are interested in new media, to catch the attention of the pupils or because they find the content of new media useful for their teaching. One-third of the teachers did not use new media and reported that they did not have sufficient knowledge on how to use new media in their English teaching. The results also show that even though new media is used by many of these teachers, the use of it is basic and few reflections are made during the use of new media. Further research about why teachers lack knowledge and how the use of new media can be extended would arguably give a better understanding of teachers’ use of pupils’ extramural English experience of new media.

Engelska

APA, Harvard, Vancouver, ISO, and other styles

48

Politis, Anastasios E. "Human capital development and competence structures in changing media production environments." Doctoral thesis, KTH, Numerical Analysis and Computer Science, NADA, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-25.

Full text

Abstract:

This doctoral thesis discusses the competence structures and the development of human capital in the graphic arts and media sector. The study has focused on exploring the new media landscape and in particular the structural changes that influence the sector, the print-versuselectronic- media debate and the future of print media. The influence of new technologies and management concepts on the graphic arts and media sector has also been investigated, as has the role and the importance of people in new societal and industrial settings as well as new ways of managing and developing people in changing media environments.

The primary research objective was to identify the competence requirements and characteristics for existing and potential employees in the graphic arts and media sector and, in particular, the areas of digital printing and cross-media publishing. The second objective was to elucidate the various actions and strategies established and applied for the professional development of people in the graphic arts and media sector, such as further training, recruitment policies and the evaluation and certification of competence. The third objective of the study was to suggest the formation of a strategy for the professional development of people in the graphic arts and media sector – namely the creation of a human capital development strategy. An important issue was to identify the various components (or substrategies) of the strategy and determine if it was possible to integrate them under a common platform.

The work has been based on literature studies, industry reports and observations, market analyses and forecasts, and empirical studies. Participatory research methods have also been used. In addition, case-study research has been performed at the company and sector levels. Human resource management and development concepts have been surveyed to determine whether they are efficient for the professional development of people in the entire spectrum of an industry sector.

The graphic arts and media sector – including print media – will remain active for the foreseeable future; however, the results presented here show that the sector has been significantly influenced by structural changes that have taken place over the last decade, affecting organizations, companies and people involved in the sector, and this process of change will continue.

The study shows that there is indeed a need for new competence in people employed in or to be recruited to the graphic arts and media sector. The initial identification and description of the competences for the new structure of the graphic arts and media industry is proposed. Various actions for the development of people in the sector, mainly regarding education, further and continuous learning, and recruitment, are also identified. However, these activities have been established mainly at the national level by various organizations (educational institutes, industrial partners and the governmental/European Union authorities).

Finally, the principal characteristics of a human capital development strategy are described, and components (or substrategies) that form a strategy that could be introduced for the graphic arts and media sector in Europe are proposed.

Keywords: Graphic arts and media sector, digital printing, cross-media publishing, human capital, intellectual capital, human resource management and development, human capital development strategy.

APA, Harvard, Vancouver, ISO, and other styles

49

Merceron, Aymeric. "Milieux granulaires réactifs : dynamique et structure autour de grains en transformation." Thesis, Paris 6, 2016. http://www.theses.fr/2016PA066473/document.

Full text

Abstract:

Les transformations physiques et chimiques qui apparaissent au sein de milieux granulaires réactifs induisent des réorganisations dynamiques et structurelles importantes. Largement utilisés pour des applications industrielles, le comportement de ces matériaux en évolution doit être compris. Dans ce travail, nous étudions expérimentalement les réarrangements d'un empilement granulaire modèle soumis à des transformations localisées d'un ou plusieurs grains. Les dispositifs expérimentaux mis au point permettent un suivi bidimensionnel de la structure environnante alors qu'un ou plusieurs grains réduisent de tailles et/ou sont tirés hors de l'empilement. La réponse moyenne du matériau aux temps longs s'apparentent aux écoulements quasi-statiques couramment observés dans les silos. Le comportement instantané de l'empilement est quant à lui très hétérogène dans l'espace et dans le temps. Il présente une dynamique intermittente avec des évènements décorrélés en temps et des ampleurs distribuées en loi de puissance. Les tailles des grains en évolution jouent un rôle important sur la réponse dynamique de l'empilement granulaire notamment en lien avec l'apparition de phénomènes de structuration pour les plus petits intrus. Par ailleurs, la présence d'un second grain en évolution à proximité d'un premier génère des effets coopératifs. Une distance caractéristique de séparation pour l'émergence de ces phénomènes est mise en évidence, elle ne dépend que de l'empilement et non de la taille des grains en évolution. Enfin, les évolutions instantanées des fractions volumiques locales montrent des distributions similaires suggérant un unique mécanisme de réarrangements structuraux
Physical and chemical transformations appearing in reactive granular media yield strong dynamical and structural reorganizations. Widely used for industrial applications, the behavior of these evolving materials needs to be understood. In this work, we experimentally study the rearrangements of a model granular packing undergoing localized transformations of one or several grains. The experimental setups allow a two-dimensional tracking of the surrounding structure while one or several grains are either reducing in size or being pulled out of the packing. The average long-term response of the material is similar to quasi-static flows commonly observed in silos. The instantaneous behavior of the packing is heterogeneous in space and time. It shows an intermittent dynamic with events decorrelated in time whose amplitudes are power-law distributed. The sizes of the evolving grains play an important role on the dynamical response of the granular packing by the appearance of arches for the smallest intruders. Moreover, the presence of a second evolving grain generates cooperative effects. A characteristic distance between the two intruders is found, it does depend on the packing properties and not on the size of the evolving grains. Finally, instantaneous evolutions of local densities show similar distributions suggesting a unique mechanism in terms of structural reorganizations

APA, Harvard, Vancouver, ISO, and other styles

50

Makryniotis, Thomas. "Identity through dress in virtual environments." Thesis, University of Kent, 2013. http://ualresearchonline.arts.ac.uk/7086/.

Full text

Abstract:

The purpose of this thesis is to examine the formation of identity through dress in virtual environments, and to establish connections between identity, fashion, and virtual reality by means of language and semiology. The notion of identity through fashion in virtual environments is examined, with fashion as a factor in identity formation through dress as analysed in structuralist terms. The virtual aspect is used both as a literal field, i.e. the medium of video games and social networks that involve virtual avatars, and as theoretical testing ground from which to derive new results on the nature of dress and many of the aspects of clothing and fashion. The practical outcome of this research, a video game based on dress and narrative, serves as an applied experiment of the three main themes in this thesis and the relations and interactions between them, as well as a testing tool with which to challenge in a practical way the theories and speculations formed in the thesis. My methodology is based on structuralism and post-structuralism in the fields of linguistics, psychology and anthropology, with particular application to the visual media and virtual reality. I am using a post-structuralist approach as it has been the most dominant discourse of replacing economic and social (power) relations with codes and the interplay between signifiers and signifieds. This, I find, is the most appropriate method for analysing both virtual systems and fashion, because, on an atomic level, they both depend on variables such as words and numbers. The code is therefore the common denominator of both disciplines. Furthermore, both disciplines use narrative for their proper function, video games for their back story and motivation of the player, and fashion for its advertising and promotion, as well as through archetypes and symbols. Fashion in this context works as a catalytic agent between post-structuralist codes in modern media as texts, and video games.

APA, Harvard, Vancouver, ISO, and other styles

Dissertations / Theses on the topic 'Median graphs'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles