Nous proposons un système complet capable de retrouver des symboles dans des documents graphiques sans connaissance a priori. Nous nous basons sur une méthode de description structurelle qui permet de mettre en avant des régions pouvant contenir un symbole. A partir d'un découpage du document en chaînes de points, nous fusionnons successivement les régions entre elles en fonction d'un critère de densité et de convexité permettant la reconstruction de symboles potentiellement intéressant pour l'utilisateur. Un descripteur est ensuite calculé pour chacun de ses symboles, ce qui permet de faire une reconnaissance quand l'utilisateur soumet une requête. Afin de réduire le temps de réponse d'une requête nous avons développé une méthode d'indexation qui se base sur l'algorithme BIRCH en utilisant un descripteur robuste et discriminant. Puis nous montrons comment réduire davantage ce temps de réponse en combinant différentes règles de filtrage basées sur des descripteurs basiques. / A complete system able to find symbols in graphical document without a priori knowledge is proposed here. In a first place, this system is based on a structural method able to put in stress regions that may contain symbols. The document is represented by chain points that will be merged following a defined criteria. These merges allow potential symbols to be reconstructed. A descriptor is then calculated for each potential symbols, and the recognition can take place when the user submit a request. In order to speed up the retrieval, an indexing method based on BIRCH has been proposed by using a robust descriptor. Then we show that by combining filtering rules based on simple descriptors, we can rise the speed of the retrieval.

Entre as trevas e a luz: o percurso labiríntico em Todos os nomes de José Saramago é uma dissertação que visa mostrar de que modo o caminho trilhado pela personagem protagonista do romance constitui um processo de autoconhecimento em meio às múltiplas possibilidades de um espaço que se configura como labiríntico. Os conceitos de símbolo, espaço, lugar, não-lugar, individuação, anima, advindos da diversidade teórica, da qual se destacam C. G. Jung (1967/ 2000/ 2007), Gilbert Durand (2002), Marc Augé (1994), Gaston Bachelard (1988/ 1990/ 1993/ 1997/ 2001), Michel de Certeau (2001), contribuíram e sistematizaram o percurso analítico do presente trabalho, que ora propomos. Nosso intuito primeiramente é verificar como os espaços da porta e da escada aparecem enquanto símbolos que levam a personagem de uma condição à outra, estabelecendo mudanças que variam entre o eu e o outro e entre as trevas e a luz, buscando também o sentido destes elementos. Em seguida, demonstramos como a imagem do labirinto é (re)construída, tanto mitologicamente (através de referências intertextuais) quanto individualmente (pelo próprio percurso da personagem) em sua passagem por portas e por escadas em espaços interiores e em espaços exteriores na busca de sua anima. / Entre as trevas e a luz: o percurso labiríntico em Todos os nomes de José Saramago is a study that aims at showing how the path chosen by the novels main character constitutes a process of self-knowledge among the multiple possibilities he comes across in a labyrinthic space. The concepts which structure and contribute to the development of this paper come from different theoretical backgrounds and include the notions of symbol, space, place, non-place, individuation and anima, as articulated by C. G. Jung (1967/ 2000/ 2007), Gilbert Durand (2002), Marc Augé (1994), Gaston Bachelard (1988/ 1990/ 1993/ 1997/ 2001), Michel de Certeau (2001). Our objective is first to consider how the space re-presented by the figures of the door and the stairs acquire symbolical value as they lead the main character from one stage to another, signaling the changes between the I and the other and between darkness and light, as he tries to unveil the meaning of such elements. Then, we focus on the way in which the image of the labyrinth is (re)constructed, both at a mythological level, through intertextual references, and at an individual level as we follow the course marked by the character in his journey through the doors and stairs he encounters in inward and outward spaces, in the pursuit of his anima.

"In modern wireless communication systems, intersymbol interference (ISI) introduced by frequency selective fading is one of the major impairments to reliable data communication. In ISI channels, the receiver observes the superposition of multiple delayed reflections of the transmitted signal, which will result errors in the decision device. As the data rate increases, the effect of ISI becomes severe. To combat ISI, equalization is usually required for symbol detectors. The optimal maximum-likelihood sequence estimation (MLSE) based on the Viterbi algorithm (VA) may be used to estimate the transmitted sequence in the presence of the ISI. However, the computational complexity of the MLSE increases exponentially with the length of the channel impulse response (CIR). Even in channels which do not exhibit significant time dispersion, the length of the CIR will effectively increase as the sampling rate goes higher. Thus the optimal MLSE is impractical to implement in the majority of practical wireless applications. This dissertation is devoted to exploring practically implementable symbol detectors with near-optimal performance in wireless ISI channels. Particularly, we focus on the design and implementation of an iterative detector based on the belief propagation (BP) algorithm. The advantage of the BP detector is that its complexity is solely dependent on the number of nonzero coefficients in the CIR, instead of the length of the CIR. We also extend the work of BP detector design for various wireless applications. Firstly, we present a partial response BP (PRBP) symbol detector with near-optimal performance for channels which have long spanning durations but sparse multipath structure. We implement the architecture by cascading an adaptive linear equalizer (LE) with a BP detector. The channel is first partially equalized by the LE to a target impulse response (TIR) with only a few nonzero coefficients remaining. The residual ISI is then canceled by a more sophisticated BP detector. With the cascaded LE-BP structure, the symbol detector is capable to achieve a near-optimal error rate performance with acceptable implementation complexity. Moreover, we present a pipeline high-throughput implementation of the detector for channel length 30 with quadrature phase-shift keying (QPSK) modulation. The detector can achieve a maximum throughput of 206 Mb/s with an estimated core area of 3.162 mm^{2} using 90-nm technology node. At a target frequency of 515 MHz, the dynamic power is about 1.096 W. Secondly, we investigate the performance of aforementioned PRBP detector under a more generic 3G channel rather than the sparse channel. Another suboptimal partial response maximum-likelihood (PRML) detector is considered for comparison. Similar to the PRBP detector, the PRML detector also employs a hybrid two-stage scheme, in order to allow a tradeoff between performance and complexity. In simulations, we consider a slow fading environment and use the ITU-R 3G channel models. From the numerical results, it is shown that in frequency-selective fading wireless channels, the PRBP detector provides superior performance over both the traditional minimum mean squared error linear equalizer (MMSE-LE) and the PRML detector. Due to the effect of colored noise, the PRML detector in fading wireless channels is not as effective as it is in magnetic recording applications. Thirdly, we extend our work to accommodate the application of Advanced Television Systems Committee (ATSC) digital television (DTV) systems. In order to reduce error propagation caused by the traditional decision feedback equalizer (DFE) in DTV receiver, we present an adaptive decision feedback sparsening filter BP (DFSF-BP) detector, which is another form of PRBP detector. Different from the aforementioned LE-BP structure, in the DFSF-BP scheme, the BP detector is followed by a nonlinear filter called DFSF as the partial response equalizer. In the first stage, the DFSF employs a modified feedback filter which leaves the strongest post-cursor ISI taps uncorrected. As a result, a long ISI channel is equalized to a sparse channel having only a small number of nonzero taps. In the second stage, the BP detector is applied to mitigate the residual ISI. Since the channel is typically time-varying and suffers from Doppler fading, the DFSF is adapted using the least mean square (LMS) algorithm, such that the amplitude and the locations of the nonzero taps of the equalized sparse channel appear to be fixed. As such, the channel appears to be static during the second stage of equalization which consists of the BP detector. Simulation results demonstrate that the proposed scheme outperforms the traditional DFE in symbol error rate, under both static channels and dynamic ATSC channels. Finally, we study the symbol detector design for cooperative communications, which have attracted a lot of attention recently for its ability to exploit increased spatial diversity available at distributed antennas on other nodes. A system framework employing non-orthogonal amplify-and-forward half-duplex relays through ISI channels is developed. Based on the system model, we first design and implement an optimal maximum-likelihood detector based on the Viterbi algorithm. As the relay period increases, the effective CIR between the source and the destination becomes long and sparse, which makes the optimal detector impractical to implement. In order to achieve a balance between the computational complexity and performance, several sub-optimal detectors are proposed. We first present a multitrellis Viterbi algorithm (MVA) based detector which decomposes the original trellis into multiple parallel irregular sub-trellises by investigating the dependencies between the received symbols. Although MVA provides near-optimal performance, it is not straightforward to decompose the trellis for arbitrary ISI channels. Next, the decision feedback sequence estimation (DFSE) based detector and BP-based detector are proposed for cooperative ISI channels. Traditionally these two detectors are used with fixed, static channels. In our model, however, the effective channel is periodically time-varying, even when the component channels themselves are static. Consequently, we modify these two detector to account for cooperative ISI channels. Through simulations in frequency selective fading channels, we demonstrate the uncoded performance of the DFSE detector and the BP detector when compared to the optimal MLSE detector. In addition to quantifying the performance of these detectors, we also include an analysis of the implementation complexity as well as a discussion on complexity/performance tradeoffs."

Made available in DSpace on 2016-04-27T17:27:09Z (GMT). No. of bitstreams: 1 Geison Amadeu Loschi.pdf: 1231487 bytes, checksum: 25b227e5ce6a2bf036c3b44c5805c9b8 (MD5) Previous issue date: 2015-03-10 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This paper comes about as an outcome of an analysis of the works of Paul Ricoeur, which are at the starting point of insertion of hermeneutics in his philosophy. It was an attempt to follow the steps of formation of his concept of symbol, which is central to that period. Decisive for this phase, also called philosophy of symbol, was to put forward the question to other disciplines that played an essential role in the analysis of symbolic language, among which is the structural anthropology of Lévi-Strauss. Thus, the terms - more specific to the dialogue established between Paul Ricoeur and Claude Lévi-Strauss on the analysis of the symbolic language of myth - were defined. Finally, this research provides a better understanding of the opening phase of the Ricoeur s hermeneutics as well as its alignments and divergences with the structuralism of Lévi-Strauss so widespread in the academic field / Este trabalho é resultado de uma análise das obras de Paul Ricoeur, que se encontram no limiar da inserção da hermenêutica em sua filosofia. Procuramos acompanhar as etapas de formação de seu conceito de símbolo, central para este período. Decisiva para esta fase, também chamada de filosofia do símbolo, foi a interpelação de outras disciplinas que se constituíram por meio da análise da linguagem simbólica, entre as quais se encontra a antropologia estrutural de Lévi-Strauss. Dessa forma, definimos os termos mais específicos do diálogo estabelecido entre Paul Ricoeur e Claude Lévi-Strauss sobre a análise da linguagem simbólica do mito. Esta pesquisa nos auxiliou a compreender melhor a fase de abertura da hermenêutica ricoeuriana e suas aproximações e afastamentos com o estruturalismo lévi-straussiano, tão difundido em nosso campo acadêmico

Bonus har under våren 2009 varit ett starkt kritiserat ämne. Flertalet skandaler har varitbelysta av media, ledare har antingen tagit emot eller efter kritik avstått från bonus i denrådande lågkonjunkturen. I denna studie behandlar vi det omtvistade ämnet bonus som ensymbol där vi söker förståelse för laddningen ordet bonus har fått. För att komma så näraverkligheten som möjligt valde vi att utföra en kvalitativ fallstudie på två företag somanvänder symbolen bonus. Studien kommer inte att resultera i en generaliseringsteoribland företag i allmänhet utan ämnar inge förståelse för specifika situationer.Förhållandet kring varje företag är unikt och måste då också behandlas därefter, studienkommer därför visa hur det kan vara inte hur det är.Vi kommer i studien ta er genom tre steg med början i empirin, för att sedan låta dig tadel av vår tolkning av ordet bonus. Slutligen hamnar vi i skedet där vi själva övertarförfattarrollen och förtydligar vikten av att tänka efter före.Vår hypotes är: Det kan vara ordet bonus som är laddat.Under resans gång upptäckte vi att symbolen innehöll oväntade egenskaper som varavgörande för studiens resultat vilket har fått oss att se bonus på ett helt nytt sätt.

Entre as trevas e a luz: o percurso labiríntico em Todos os nomes de José Saramago é uma dissertação que visa mostrar de que modo o caminho trilhado pela personagem protagonista do romance constitui um processo de autoconhecimento em meio às múltiplas possibilidades de um espaço que se configura como labiríntico. Os conceitos de símbolo, espaço, lugar, não-lugar, individuação, anima, advindos da diversidade teórica, da qual se destacam C. G. Jung (1967/ 2000/ 2007), Gilbert Durand (2002), Marc Augé (1994), Gaston Bachelard (1988/ 1990/ 1993/ 1997/ 2001), Michel de Certeau (2001), contribuíram e sistematizaram o percurso analítico do presente trabalho, que ora propomos. Nosso intuito primeiramente é verificar como os espaços da porta e da escada aparecem enquanto símbolos que levam a personagem de uma condição à outra, estabelecendo mudanças que variam entre o eu e o outro e entre as trevas e a luz, buscando também o sentido destes elementos. Em seguida, demonstramos como a imagem do labirinto é (re)construída, tanto mitologicamente (através de referências intertextuais) quanto individualmente (pelo próprio percurso da personagem) em sua passagem por portas e por escadas em espaços interiores e em espaços exteriores na busca de sua anima. / Entre as trevas e a luz: o percurso labiríntico em Todos os nomes de José Saramago is a study that aims at showing how the path chosen by the novels main character constitutes a process of self-knowledge among the multiple possibilities he comes across in a labyrinthic space. The concepts which structure and contribute to the development of this paper come from different theoretical backgrounds and include the notions of symbol, space, place, non-place, individuation and anima, as articulated by C. G. Jung (1967/ 2000/ 2007), Gilbert Durand (2002), Marc Augé (1994), Gaston Bachelard (1988/ 1990/ 1993/ 1997/ 2001), Michel de Certeau (2001). Our objective is first to consider how the space re-presented by the figures of the door and the stairs acquire symbolical value as they lead the main character from one stage to another, signaling the changes between the I and the other and between darkness and light, as he tries to unveil the meaning of such elements. Then, we focus on the way in which the image of the labyrinth is (re)constructed, both at a mythological level, through intertextual references, and at an individual level as we follow the course marked by the character in his journey through the doors and stairs he encounters in inward and outward spaces, in the pursuit of his anima.

This thesis explores the view on symbol, body and freedom in Paul Ricoeur's and Olivier Clément's work. The aim is to analyse symbols and explore the benefits they can have for modern society, Western culture and how can these symbols influence people. This topic indirectly allows understanding of the role of tradition, rituals, narrations, myths and traditional wisdom in nowadays Western society. Furthermore, the thesis shows what influences the process of thinking, deciding and deepening one's faith. In particular, I am investigating whether in nowadays democratic and freedom supporting society one really has possibility of free choice. This reflection is to be completed on the basis of previous analysis of the symbol, body and freedom in the view of philosopher Paul Ricoeur and theologian Olivier Clément. The thesis is structured into three chapters. The first chapter is dedicated to the analysis of Ricoeur's view on this subject, in the following chapter I study Clément's theology, and in the third chapter I offer the comparison of these two. In the beginning of each chapter I introduce the life of the authors and influences that they encountered. This will reveal their philosophy and theology in better context. The conclusion summarizes the findings of previous chapters, and shows how they can...

Modern scholarly theories of oral folk narrative suggest that urban legends contain expressions of cultural beliefs that can be understood both through the contexts in which these stories are told and through the elements of the stories that remain constant across multiple tellings by various narrators. This study centers exclusively on stories and popular culture products that utilize missing or damaged fingers, hands, or arms, in order to identify the cultural values that are attached to hands in American culture. These stories in particular were chosen because the severed hand was perceived at the onset to be a common element within stories that had not been broadly analyzed. The particular theories that drive this study are drawn from the fields of folklore, disability studies, psychology, and neuroscience, and suggest that stories about severed hands express belief about the nature of humanity. Once the hypothesis was formed, I turned to the Fife Folklore Archives of the Merril-Cazier Library at Utah State University in order to collect transcripts of interviews in which severed hand legends had been told. Three hundred fifty potential texts were initially identified, and two hundred fifty featured a mention of severed hands. Those texts were then classified by what role the severed hand played in the course of the story into three distinct categories: villains with severed hands and prosthetics, victims who lose hands in the course of the narrative, and severed hands appearing in pranks or as contaminants. The narratives of each category were then analyzed, and themes of evil, risk, safety, and crossed boundaries began to emerge. To verify the cultural themes of the textual study, popular culture narratives were then analyzed to determine if similar themes were expressed. This set of narratives included movies, television, comic books, and novels. While the same themes were expressed in these narratives, the categories of evil and crossed boundaries each featured subverted forms of heroism and hands as characters as well, all of which supported the original interpretation. The results indicate that severed hands in American narratives represent lost humanity, and therefore that the hand is a vital part of how individuals within the culture might perceive their own humanity.

When studyind elliptic operators on manifolds with nonisolated singularities one naturally encounters families of conormal symbols (i.e. operators elliptic with parameter p ∈ IR in the sense of Agranovich-Vishik) parametrized by the set of singular points. For homotopies of such families we define the notion of spectral flow, which in this case is an element of the K-group of the parameter space. We prove that the spectral flow is equal to the index of some family of operators on the infinite cone.

Med denna uppsats måste jag verkligen betona att jag ökat min förståelse för Takashi Murakami och hans konstnärskap. Gradvis tog jag mig in i hans konstnärskap. Till en början är det väldigt lätt att fastna vid spektakulära uttryck i hans konst och grubblerier kring hur hans varor blivit konst, men glappet däremellan är alldeles för stort för att sådana tankar skall kunna mynna ut i något fruktbart. Men genom att först försöka förstå sig på hans verksamhet mot ljuset av den ekonomiska kontexten framhävdes gradvis detaljerna kring hur hans varor blivit konst. Jag kom fram till att hans konst egentligen handlar om symboler i relation till andra symboler, där spänningen ligger i att Murakamis är beständiga/ fixerade medan de övriga är rörliga/ dynamiska. Utan Murakamis beständiga/ fixerade symboler som retar den så tillsynes naturliga harmonin i det rörliga/ dynamiska hav av övriga ekonomiskt knutna symboler hade jag definitivt inte förstått att dem är rörliga.