Dissertations / Theses on the topic 'Internal reconstruction'

Diffuse Optical Tomography (DOT) has been applied to imaging functional activations in the adult brain. Registered-atlas models are acceptable alternative forward models for the subject-specific models. In this work, different landmark-based rigid registration methods are quantitatively evaluated and compared in geometrical accuracy of the registration result, accuracy of light propagation approximation and recovery accuracy of the brain activations based on the whole head and localized head regions. The most suitable registration methods are selected based on accuracy and efficiency and they vary based on region of interest. For example, the most suitable registration method for recovery of whole cortex activation is the registration method based on 19 landmarks from the EEG 10/20 system and non-iterative Point to Point algorithms (EEG19nP2P registration). Efficiency of the recovery process is another popular research area in DOT. In this work, a modified generation approach of the light propagation approximation is designed based on a reduced sensitivity matrix and parallelisation process. It improves the storage efficiency by >1000% and time efficiency by ~400%. Based on this approach, the brain activation recovery of DOT can be processed on a normal laptop without large memory requirements within 45 minutes which is more suitable for a portable system.

Orientadores: Luis Felipe de Toledo Ramos Pereira, Renato Neves Feio<br>Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia<br>Made available in DSpace on 2018-08-27T16:33:55Z (GMT). No. of bitstreams: 1 Nunes-de-Almeida_CarlosHenriqueLuz_M.pdf: 2724728 bytes, checksum: 32daa352df879ffab82840075e1dc3f6 (MD5) Previous issue date: 2015<br>Resumo: Os anfíbios da família Cycloramphidae são endêmicos da porção oriental do Brasil e alguns estão ameaçados ou em perigo de extinção. Apesar de ser uma família com poucos grupos taxonômicos, apenas três gêneros (Cycloramphus, Thoropa e Zachaenus), até o momento não há uma proposta filogenética para o gênero Thoropa que abranja todas as espécies. Então, propomos a reconstrução filogenética de Thoropa usando como grupo esterno, uma espécie do gênero Hylodes (Hylodidae), duas do gênero Cycloramphus e uma espécie do gênero Zachaenus. Definimos 86 caracteres baseados em osteologia, ecologia e morfologia externa de adultos e larvas. Neste contexto realizamos a descrição da forma larval de Cycloramphus rhyakonastes, a qual foi utilizada como grupo esterno. A filogenia proposta é baseada em critérios de máxima parcimônia. Como duas das árvores resultantes indicam parafilia, propomos aqui um novo gênero para as espécies de menor porte, separando-as das espécies maiores<br>Abstract: The phylogenetic resolution of Neotropical amphibians increased considerably in recent decades, providing great understanding of the relationships of higher taxa, such as the relationships between families and genera. After such improvement, amphibian systemticians are now focusing their efforts on lower taxa, such as the relationships within congeneric species. Under such context we did a phylogenetic reconstruction of the genus Thoropa, for which no comprehensive phylogeny is available. We examined all species of the genus including two species with extinct populations and possible new species. We adopted the criteria of maximum parsimony to analyze 86 characters based on osteology, external morphology, behavior, bioacoustics, and tadpole external morphology of at least one specimen per species. As the resulting topology of Thoropa tree indicates a possible case of paraphyly, we propose a new genus, assuring the monophyly of Thoropa in all possible scenarios<br>Mestrado<br>Biodiversidade Animal<br>Mestre em Biologia Animal

In a mobile robotic system, the interaction with the surrounding environment is essential in order to complete tasks such as localisation and mapping. This interaction can only be conducted by means of sensors that permit the accumulation of a large amount of information from several sources. However, this information is useless without adequate interpretation; thus, in order to accurately determine the positioning of the robot, it is necessary to identify and characterise landmarks in the environment required to serve as anchoring points for both localisation and mapping. Having constructed the map, an accurate analysis of the information gathered is vital. In this manner, this work is focused on two main aspects of any mobile robotic system: first, the detection and characterisation of highly descriptive landmarks by using image and point cloud processing techniques; and second, the geometrical and spatial analysis of the information gathered from the environment. For the former, two novel techniques based on image processing and geometrical analysis are presented; for the latter, a guaranteed technique for the parameter estimation of primitive shapes using interval analysis is proposed.

L’objectif de ces travaux de thèse est de proposer des approches bayésiennes “physiquement informées” pour l’estimation de directions d’arrivée de sources acoustiques sous-marines dans un milieu océanique fluctuant. Dans un premier temps nous verrons donc comment décrire ces fluctuations comme perturbation locale de la célérité du milieu pour ensuite décrire leur impact sur la propagation d’une onde et la mesure de celle-ci. Ce faisant nous pourrons décrire la dégradation subie par le signal, motivant la création d’un modèle statistique pour décrire cette perturbation. Après un état de l’art sur les méthodes d’estimation des directions d’arrivées (DOA), tout d’abord en milieu constant, puis en milieu incertain, nous définirons une modélisation de ces fluctuations sous forme d’un bruit de phase structuré selon une distribution gaussienne multivariée. Nous verrons que ce choix nous rapproche du modèle théorique de structure défini dans le premier chapitre. Cette modélisation nous permet alors de proposer la méthode paSAMP, algorithme d’Approximate Message Passing, inspirée des méthodes de reconstruction de phase et se révélant plus robuste au bruit additif, ainsi qu’au bruit de phase structuré, que les méthodes d’estimation des DOA classiques. Dans un deuxième temps, nous proposerons de réviser notre modélisation statistique et de considérer un bruit de phase distribuée selon une loi de Von Mises multivariée. Cette distribution permet une modélisation plus fidèle des bruits de phase. Considérant ce nouveau modèle, nous dériverons deux nouvelles méthodes : VitAMin et VistaBEM, respectivement extensions de paSAMP et paVBEM, déjà présent dans la littérature et reposant sur une autre approximation variationnelle bayésienne. Les premiers résultats, réalisés sur des données synthétiques considérant un modèle plus simple de VonMises unidimensionnel, s’avèrent prometteurs quant à la bonne intégration des modèles considérés et ainsi à leur robustesse au bruit de phase distribué selon ce modèle. Pour finir nous verrons que par le traitement de données réelles, il nous est possible d’extraire les mêmes grandeurs caractéristiques que celles décrites par le modèle théorique, mais également d’identifier certaines ondes internes spécifiques. Ceci à des fins de caractérisation rapide des fluctuations du milieu par méthode passive ou encore pour une initialisation informée des algorithmes proposés<br>The purpose of these works is to propose new "physically informed" bayesian algorithms for DOA estimationin presence of random fluctuations due to the presence of internal waves in the propagation medium. First we will seehow to describe these fluctuations as a local perturbation of the celerity of the medium and then the impact of such waveson a propagated signal. In doing so, we are able to observe the corruption of this signal and to propose a statistical modelof this perturbation.After a state of the art of DOA estimation techniques in both constant an uncertain media, we will propose a modelizationof the fluctuations as a multiplicative phase noise following a multivariate gaussian distribution. Very close to thetheoretical model, this distribution allows us to develop the paSAMP algorithm, an Approximate Message Passingtechnique inspired form phase retrieval litterature which integrates this multiplicative phase noise model. In order to getcloser to the theoretical model, we propose to upgrade the phase noise prior using a multivariate Von Mises prior,allowing us to propose new bayesian methods for DOA estimation such as the VitAMin and the VistaBEM algorithms asextensions of resp. the paSAMP and the paVBEM algorithms. The first results on synthetic measurement considering aunivariate Von Mises phase noise seems are promising regarding the robustness of these algorithms to this new noisemodel.To conclude, we will see with the processing of real data from the ALMA campaign that it is possible to retrieve quantitiesfrom the theoretical model through signal statistics. Moreover, these quantities allow us to identify known phenomenon inthe propagation medium with only passive measurement. Such knowledge can then be use for tomography or as "smartinitialization" of the different algorithms

Beaucoup de services vitaux de la vie quotidienne dépendent de systèmes d'ingénierie hautement complexes et interconnectés; Ces systèmes sont constitués d'un grand nombre de capteurs interconnectés, d'actionneurs et de composants du système. L'étude des systèmes interconnectés joue un rôle important dans l'étude de la fiabilité des systèmes dynamiques; car elle permet d'étudier les propriétés d'un système interconnecté en analysant ses sous-composants moins complexes. Le diagnostic des pannes est essentiel pour assurer des opérations sûres et fiables des systèmes de contrôle interconnectés. Dans toutes les situations, le système global et / ou chaque sous-système peuvent être analysés à différents niveaux pour déterminer la fiabilité du système global. Dans certains cas, il est important de déterminer les informations anormales des variables internes du sous-système local, car ce sont les causes qui contribuent au fonctionnement anormal du processus global. Cette thèse porte sur les défis de l'application de la théorie inverse du système et des techniques FDD basées sur des modèles pour traiter le problème articulaire du diagnostic des fautes et de l'analyse des causes racines (FD et RCA). Nous étudions ensuite le problème de l'inversibilité de la gauche, de l'observabilité et de la diagnosticabilité des fauts du système interconnecté, formant un algorithme FD et RCA multi-niveaux basé sur un modèle. Ce système de diagnostic permet aux composants individuels de surveiller la dynamique interne localement afin d'améliorer l'efficacité du système et de diagnostiquer des ressources de fautes potentielles pour localiser un dysfonctionnement lorsque les performances du système global se dégradent. Par conséquent, un moyen d'une combinaison d'intelligence locale avec une capacité de diagnostic plus avancée pour effectuer des fonctions FDD à différents niveaux du système est fourni. En conséquence, on peut s'attendre à une amélioration de la localisation des fauts et à de meilleurs moyens de maintenance prédictive. La nouvelle structure du système, ainsi que l'algorithme de diagnostic des fautes, met l'accent sur l'importance de la RCA de défaut des dispositifs de terrain, ainsi que sur l'influence de la dynamique interne locale sur la dynamique globale. Les contributions de cette thèse sont les suivantes: Tout d'abord, nous proposons une structure de système non linéaire interconnecté inversible qui garantit le fauts dans le sous-système de périphérique de terrain affecte la sortie mesurée du système global de manière unique et distincte. Une condition nécessaire et suffisante est développée pour assurer l'inversibilité du système interconnecté qui nécessite l'inversibilité de sous-systèmes individuels. Deuxièmement, un observateur interconnecté à deux niveaux est développé; Il se compose de deux estimateurs d'état, vise à fournir des estimations précises des états de chaque sous-système, ainsi que l'interconnexion inconnue. En outre, il fournira également une condition initiale pour le reconstructeur de données et le filtre de fauts local une fois que la procédure FD et RCA est déclenchée par tout fauts. D'une part, la mesure utilisée dans l'estimateur de l'ancien sous-système est supposée non accessible; La solution est de la remplacer par l'estimation fournie par l'estimateur de ce dernier sous-système<br>Many of the vital services of everyday life depend on highly complex and interconnected engineering systems; these systems consist of large number of interconnected sensors, actuators and system components. The study of interconnected systems plays a significant role in the study of reliability theory of dynamic systems, as it allows one to investigate the properties of an interconnected system by analyzing its less complicated subcomponents. Fault diagnosis is crucial in achieving safe and reliable operations of interconnected control systems. In all situations, the global system and/or each subsystem can be analyzed at different levels in investigating the reliability of the overall system; where different levels mean from system level down to the subcomponent level. In some cases, it is important to determine the abnormal information of the internal variables of local subsystem, in order to isolate the causes that contribute to the anomalous operation of the overall process. For example, if a certain fault appears in an actuator, the origin of that malfunction can have different causes: zero deviation, leakage, clogging etc. These origins can be represented as root cause of an actuator fault. This thesis concerns with the challenges of applying system inverse theory and model based FDD techniques to handle the joint problem of fault diagnosis &amp; root cause analysis (FD &amp; RCA) locally and performance monitoring globally. By considering actuator as individual dynamic subsystem connected with process dynamic subsystem in cascade, we propose an interconnected nonlinear system structure. We then investigate the problem of left invertibility, fault observability and fault diagnosability of the interconnected system, forming a novel model based multilevel FD &amp; RCA algorithm. This diagnostic algorithm enables individual component to monitor internal dynamics locally to improve plant efficiency and diagnose potential fault resources to locate malfunction when operation performance of global system degrades. Hence, a means of acombination of local intelligence with a more advanceddiagnostic capability (combining fault monitoring anddiagnosis at both local and global levels) to performFDDfunctions on different levels of the plantis provided. As a result, improved fault localization and better predictive maintenance aids can be expected. The new system structure, together with the fault diagnosis algorithm, is the first to emphasize the importance of fault RCA of field devices, as well as the influences of local internal dynamics on the global dynamics. The developed model based multi-level FD &amp; RCA algorithm is then a first effort to combine the strength of the system level model based fault diagnosis with the component level model based fault diagnosis. The contributions of this thesis include the following: Firstly, we propose a left invertible interconnected nonlinear system structure which guarantees that fault occurred in field device subsystem will affect the measured output of the global system uniquely and distinguishably. A necessary and sufficient condition is developed to ensure invertibility of the interconnected system which requires invertibility of individual subsystems. Second, a two level interconnected observer is developed which consists of two state estimators, aims at providing accurately estimates of states of each subsystem, as well as the unknown interconnection. In addition, it will also provide initial condition for the input reconstructor and local fault filter once FD &amp; RCA procedure is triggered by any fault. Two underlyingissues are worth to be highlighted: for one hand, the measurement used in the estimator of the former subsystem is assumed not accessible; the solution is to replace it by the estimate provided by the estimator of the latter subsystem. In fact, this unknown output is the unknown interconnection of the interconnected system, and also the input of the latter subsystem

The generated HTTP traffic of users' interactions with a Web application can be logged for further analysis. In this thesis, we present the ``Session Reconstruction'' problem that is the reconstruction of user interactions from recorded request/response logs of a session. The reconstruction is especially useful when the only available information about the session is its HTTP trace, as could be the case during a forensic analysis of an attack on a website. New Web technologies such as AJAX and DOM manipulation have provided more responsive and smoother Web applications, sometimes called ``Rich Internet Applications''(RIAs). Despite the benefits of RIAs, the previous session reconstruction methods for traditional Web applications are not effective anymore. Recovering information from a log in RIAs is significantly more challenging as compared with classical Web applications, because the HTTP traffic contains often only application data and no obvious clues about what the user did to trigger that traffic. This thesis studies applying different techniques for efficient reconstruction of RIA sessions. We define the problem in the context of the client/server applications, and propose a solution for it. We present different algorithms to make the session reconstruction possible in practice: learning mechanisms to guide the session reconstruction process efficiently, techniques for recovering user-inputs and handling client-side randomness, and also algorithms for detections of actions that do not generate any HTTP traffic. In addition, to further reduce the session reconstruction time, we propose a distributed architecture to concurrently reconstruct a RIA session over several nodes. To measure the effectiveness of our proposed algorithms, a prototype called D-ForenRIA is implemented. The prototype is made of a proxy and a set of browsers. Browsers are responsible for trying candidate actions on each state, and the proxy, which contains the observed HTTP trace, is responsible for responding to browsers' requests and validating attempted actions on each state. We have used this tool to measure the effectiveness of the proposed techniques during session reconstruction process. The results of our evaluation on several RIAs show that the proposed solution can efficiently reconstruct use-sessions in practice.

Les dernières décennies ont connu l’essor des communications numériques. Ceci a donné lieu à la prolifération des standards de communication, ce qui demande une plus grande adaptabilité des systèmes de communication. Une manière de rendre ces systèmes plus flexibles consiste à concevoir un récepteur intelligent qui serait capable de retrouver l’ensemble des paramètres de l’émetteur. Dans ce manuscrit, nous nous intéressons à l’identification en aveugle des codes correcteurs d’erreurs. Nous proposons des méthodes originales, basées sur le calcul de distances euclidiennes entre des séquences de symboles bruités. Tout d’abord, un premier algorithme de classification permet la détection d’un code puis l’identification de la longueur de ses mots de code. Un second algorithme basé sur le nombre de collisions permet quand à lui d’identifier la longueur des mots d’informations. Ensuite, nous proposons une autre méthode utilisant cette fois les distances euclidiennes minimales pour l’identification de la longueur d’un code en bloc. Enfin, une méthode de reconstruction du code dual d’un code correcteur d’erreurs est présentée<br>Recent decades have seen the rise of digital communications. This has led to a proliferation of communication standards, requiring greater adaptability of communication systems. One way to make these systems more flexible is to design an intelligent receiver that would be able to retreive all the parameters of the transmitter from the received signal. In this manuscript, we are interested in the blind identification of error-correcting codes. We propose original methods based on the calculation of Euclidean distances between noisy symbol sequences. First, a classification algorithm allows the detection of a code and then the identification of its code words lenght. A second algorithm based on the number of collisions allows to identify the length of the information words. Then, we propose another method using the minimum Euclidean distances to identify block codes length. Finally, a method for reconstructing the dual code of an error-correcting code is presented

The goal of our projectis to „restart“ the Jaroslavice village. It was a well established settlement before the war, but has been on a downfall ever since. The problem began by eviction of german population after the war, followed by close distance to highly guarded border. This project is aiming on the possibility of living in the „ near border area and resumption of forgotten countryside. It proposes to connect old with new. The core of the project is renovation of majer near the castle. It is located on the edge of Jaroslavice and is connected to newly established part of the village. The site of the majer is becomming a connection point of history and present. Therefore, the object provides areas needed by students of newly designed high school. It includes accomodation, cafeteria and residental yard. It blends with additional areas of art centre nearby and is connected to the centre of village. Among the functions ths project provides, there is also a variable hall desired by village management.

Dans cette thèse, nous élaborons, dans le cadre méthodologique de la physique quantique, un cadre variationnel générique en traitement d'images bas niveau, fondé sur le principe de l'Information Physique Extrême. Nous utilisons cet outil, récemment développé, pour dériver, entre autres, la théorie des espaces d'échelles, et retrouver des diffusions linéaires et non linéaires classiques. Cette approche permet d'être optimal au sens d'un compromis entre imprécision des mesures et incertitude sur le phénomène mesuré. A ce nouveau modèle variationnel on associe l'équation de Klein-Gordon avec champs, ou en limite, celle de Schrödinger avec champs.<br />L'application associée concerne la détection et la reconstruction de prothèses coronaires, autrement appelées stents, à partir d'images rayons X. Notre méthode s'apparente à une méthode de reconstruction 2D-3D orientée forme. En effet, nous couplons deux équations de Schrödinger avec champs. Cette écriture nous permet de tirer pleinement parti de l'acquisition tomographique, ainsi que d'une contrainte de ressemblance avec un modèle d'objet à reconstruire. Chacune de ces deux sources d'information est ainsi traduite de manière algorithmique par une équation de Schrödinger. An de déterminer un potentiel d'attraction du modèle 2D vers la projection du stent, nous avons développé un nouveau descripteur multi-local ou de la surface de luminance d'une image, ainsi que deux algorithmes pragmatiques de détection et de localisation de pixels appartenant à la projection du stent.

En médecine nucléaire, les images de Tomographie d'Emission Mono-Photonique (TEMP) permettent de diagnostiquer un certain nombre de maladies dégénératives, comme la maladie de Parkinson. Le principe de ce type de diagnostic est de comparer l'activité reconstruite au sein de deux régions d'intérêt particulières. Cette comparaison est problématique car les mesures ayant des fluctuations aléatoires, les activités reconstruites en ont aussi. La statistique de ces fluctuations étant inconnue, le diagnostic obtenu est souvent peu fiable. Pour rendre ce type de diagnostic plus fiable, il est important de quantifier, dans chaque région d'intérêt, l'impact des fluctuations aléatoires des mesures de projection sur l'activité reconstruite. Dans cette thèse, nous nous intéressons à cette quantification via des méthodes de reconstruction basées sur une nouvelle modélisation du processus d'acquisition tomographique. Une des particularités de ces méthodes est que les valeurs des activités reconstruites ne sont pas des valeurs précises mais des intervalles d'activités. Une propriété importante de ces estimations intervallistes est que la largeur des intervalles quantifie l'erreur statistique de reconstruction. Une contribution importante de ce travail est la mise en place d'un protocole dérivé de la méthode de comparaison quantitative appliquée en routine clinique. Ce protocole peut être utilisé, d'une part, pour évaluer la performance d'une méthode de quantification d'erreur dans une tâche de comparaison d'activités reconstruites et d'autre part, pour comparer les performances de plusieurs algorithmes de quantification. Nous montrons et discutons les performances de deux méthodes de quantification intervallistes et d'une méthode de quantification choisie comme référence<br>In nuclear medicine, Single-Photon Emission Computed Tomography (SPECT) images are used to diagnose a certain number of degenerative diseases such as Parkinson's disease. The principle of this kind of diagnosis is to compare the activity reconstructed in two specific regions of interest. The random fluctuations of the reconstructed activities, due to the random fluctuations of the measurement, have unknown statistical properties. This lack of knowledge makes the comparison, and thus the diagnosis, unreliable. To make the diagnosis more reliable, it is important to quantify the impact of random fluctuations of the projection measurements on the reconstructed activities in each region of interest.In this thesis, we focused on this quantification by using reconstruction methods based on a new modelling of the acquisition tomography process. A special feature of the obtained reconstructions is that the reconstructed activities are not precise- but interval-valued activities. The width of the reconstructed intervals quantifies the reconstruction error. As important contribution, we have proposed a protocol derived from the quantitative comparison method applied in clinical routine. This protocol can be used to evaluate the performance of an error quantification algorithm or, to compare the performances of two quantification algorithms. We show and discuss the performance of two interval-based quantification methods and a chosen reference method

INTRODUÇÃO: O tratamento das neoplasias malignas anorretais exige ressecções que podem levar ao surgimento de defeitos perineais extensos. Esses defeitos necessitam de reconstrução que deve ser realizada, preferencialmente, com retalhos. Dentre eles, destacamos o retalho perfurante da artéria pudenda interna, localizado no sulco glúteo, vascularizado por vasos perfurantes cutâneos da artéria pudenda interna, e inervado por ramos do nervo pudendo e do nervo cutâneo femoral posterior. Esse retalho apresenta diversas vantagens em comparação com os outros utilizados para reconstrução perineal, e os dados relacionados à avaliação de sua sensibilidade cutânea são escassos, discrepantes e sujeitos a críticas metodológicas. OBJETIVO: Avaliar a sensibilidade cutânea do retalho perfurante da artéria pudenda interna após 12 meses da reconstrução perineal em cirurgias de amputação abdominoperineal de reto, e compará-la com a sensibilidade cutânea pré-operatória do sulco glúteo (área doadora do retalho). MÉTODOS: Estudo prospectivo com 25 pacientes submetidos à amputação abdominoperineal de reto por neoplasias malignas anorretais e reconstruídos com o retalho perfurante da artéria pudenda interna de avanço VY bilateral. As modalidades de sensibilidade tátil, dolorosa, térmica e vibratória foram analisadas em quatro áreas do sulco glúteo no pré-operatório e nas quatro áreas correspondentes do retalho 12 meses após a cirurgia. A avaliação da sensibilidade tátil foi realizada com o Pressure Specified Sensory Device(TM) (PSSD(TM)), aparelho que quantifica a pressão aplicada à pele, estática ou em movimento. As outras modalidades de sensibilidade foram analisadas com o método de escolha forçada, utilizando ponta de agulha para sensibilidade dolorosa, contato quente/frio para sensibilidade térmica e diapasão de 128 Hz para sensibilidade vibratória. RESULTADOS: Os limiares de sensibilidade tátil medidos com o PSSD(TM) no retalho perfurante da artéria pudenda interna após 12 meses da reconstrução perineal foram semelhantes aos limiares de sensibilidade tátil no sulco glúteo no pré-operatório, tanto no teste de pressão estática quanto em movimento. A comparação entre esses limiares não apresentou diferença estatisticamente significante, com valores de p superiores a 0,05 nas quatro áreas avaliadas, para ambos os testes. Todos os pacientes apresentaram sensibilidade dolorosa, térmica e vibratória nas quatro áreas testadas, tanto no sulco glúteo no pré-operatório quanto no retalho após 12 meses da cirurgia. CONCLUSÃO: Nas reconstruções perineais após amputação abdominoperineal de reto, espera-se que a sensibilidade cutânea do retalho perfurante da artéria pudenda interna seja mantida<br>INTRODUCTION: The treatment of anorectal malignancies requires resection that can lead to extensive perineal defects. These defects require reconstruction which should be performed, preferably, with flaps. Among them, we highlight the internal pudendal artery perforator flap, located on the gluteal fold, vascularized by cutaneous perforator vessels from the internal pudendal artery, and innervated by branches from the pudendal nerve and the posterior femoral cutaneous nerve. This flap has many advantages compared to others used for perineal reconstruction, and data related to the evaluation of its cutaneous sensibility are scarce, discrepant and subject to methodological criticisms. OBJECTIVE: To evaluate cutaneous sensibility of the internal pudendal artery perforator flap 12 months after perineal reconstruction in abdominoperineal resection of rectum, and compare it with the preoperative cutaneous sensibility of the gluteal fold (flap donor area). METHODS: A prospective study of 25 patients undergoing abdominoperineal resection of rectum for anorectal malignancies, and reconstruction with the internal pudendal artery perforator flap, in bilateral VY advancement. The modalities of tactile, pain, thermal and vibration sensibility were analyzed in four areas of the gluteal fold preoperatively and in the four corresponding areas of the flap 12 months after surgery. Tactile sensibility was assessed using the Pressure Specified Sensory Device(TM) (PSSD(TM)), a device that measures the pressure applied to the skin, static or moving. The other types of sensibility were analyzed with the forced-choice method, using a needle for pain sensibility, hot/cold contact for thermal sensibility and 128 Hz tuning-fork for vibration sensibility. RESULTS: The tactile sensibility thresholds measured with PSSD(TM) on the internal pudendal artery perforator flap 12 months after perineal reconstruction were similar to tactile sensibility thresholds of the gluteal fold preoperatively, both in static and moving pressure tests. The comparison between these thresholds showed no statistically significant difference, with p values greater than 0.05 in the four areas evaluated, for both tests. All patients presented pain, thermal and vibration sensibility in all four areas tested, on the both the gluteal fold preoperatively and the flap 12 months after surgery. CONCLUSION: In perineal reconstructions after abdominoperineal resection of rectum, it is expected that the cutaneous sensibility of the internal pudendal artery perforator flap is maintained

La comprensión de la anatomía vascular de una perforante individual en relación con su territorio vascular es esencial para el diseño óptimo de un colgajo. Siendo la definición del territorio vascular distal una de las limitaciones de los colgajos de perforantes locales, a menudo hay problemas con el drenaje venoso y necrosis distal. Con el diseño clásico de perforantes del colgajo de la arteria mamaria interna (IMAP) basado en el colgajo deltopectoral, estos problemas eran comunes en ciertas longitudes. Con una mejor definición de axialidad y un rediseño podemos disminuirlos. El objetivo del estudio fue investigar la axialidad de esta perforante en el tórax para optimizar el diseño del colgajo IMAP. Estudiamos el trayecto de la perforante dominante de la arteria mamaria interna en 140 pacientes consecutivos sometidos a una tomografía computarizada de multidetectores (MDTC) de seguimiento en diversas patologías. Se excluyeron los pacientes que habían sido sometidos a cirugía de tórax. Todos los estudios angiográficos se realizaron en el mismo centro y la evaluación se hizo en colaboración con el mismo radiólogo. El curso anatómico de la perforante de la mamaria interna dominante fue definido y medido en ambos lados del tórax en relación a las referencias anatómicas, tales como el complejo areola-pezón. Disecamos 16 piezas anatómicas, 32 perforantes dominantes de la arteria mamaria interna. Cadáveres en fresco 10, y en solución de Cambdrige 6. Realizamos las mediciones de calibre, longitud y trayecto en relación con el complejo areola-pezón. El MDCT reveló el curso de perforante dominante en todos los casos. El diámetro más grande se encuentra en el segundo espacio intercostal en el 58% de los casos. La axialidad medida de la perforante fue hacia el complejo areola-pezón en el 64% de los pacientes. Igualmente, en las disecciones anatómicas, observamos el trayecto de la perforante en dirección al complejo areola-pezón Discutimos aplicaciones clínicas del colgajo IMAP en reconstrucción de cabeza y cuello, siendo su indicación principal. Así como reconstrucción de defectos en tórax, contrastando el diseño previo y el nuevo diseño propuesto del colgajo IMAP, y también nuevas indicaciones como la reconstrucción de mama. Se determinó el patrón axialidad dominante de la perforante principal de la arteria mamaria interna en el colgajo IMAP. Con el nuevo diseño para este colgajo en dirección al complejo areola-pezón, se observa una disminución en la tasa distal problemas vasculares, incluso en los grandes colgajos.<br>Understanding the vascular anatomy of an individual perforator relative to its vascular territory is essential to optimal flap design. Being the definition of the distal vascular territory one of the limitations of local perforator flaps, there are often problems with venous drainage and distal necrosis. With the classic design of perforator flap of the internal mammary artery (IMAP) based deltopectoral flap, these problems were common at certain lengths. With a better definition of axiality and a redesign we can diminish it. The study’s aim was to investigate the axiality of this perforator in the thorax to optimize IMAP flap design. The course of the internal mammary perforator in a prospective, single-blind, cohort study in 140 consecutive patients undergoing multidetector-row computed tomographic (MDTC) angiography for follow-up in various pathologies was carried out. Patients who had had chest surgery were excluded. All of the angiographic studies were performed in the same center and the assessment was done in collaboration with the same radiologist. The anatomical course of the dominant internal mammary perforator was mapped and measured on both sides of the chest in relation to anatomical references such as the nipple-areola complex. 16 anatomical specimens, 32 internal mammary perforators, 10 fresh cadavers and 6 in a Cambdrige solution were dissected. Caliber, length and course measurements in relation to the nipple-areola complex were performed. MDCT revealed the course of the dominant perforator in all cases. The largest diameter was located in the second intercostal space in 58% of the cases. The perforating vessel axiality ran towards the nipple-areola complex in 64% of the patients. Likewise, the path of the piercing toward the nipple-areola complex has been observed in anatomical dissections. Clinical IMAP flap applications in head and neck reconstruction, its main indication, were discussed. Also the chest defects’ reconstruction, contrasting the previous design, and the proposed new IMAP flap design, and new indications such as breast’s reconstruction were discussed. The dominant axiality pattern of the dominant internal mammary perforator vessels in the IMAP flap was determined. With the new design for this flap, a decrease in the distal vascular problems rate was even observed in big flaps.

INTRODUÇÃO: As reconstruções com tecidos combinados e bem vascularizados permitem a melhor reabilitação para defeitos extensos em cabeça e pescoço. O padrão-ouro tem sido as transferências microcirúrgicas de tecidos. Porém, há pacientes em que não há vasos receptores cervicais adequados para os transplantes de tecidos livres devido à múltiplas recidivas, ressecções e reconstruções; linfadenectomias cervicais; fístulas e infecções; e o tratamento com radioterapia. Com o aprimoramento do controle oncológico, pacientes nestas circunstâncias são cada vez mais frequentes e há poucas alternativas para reconstrução. OBJETIVO: Descrever a dissecação anatômica de um retalho osteomiocutâneo combinado, pediculado nos vasos torácicos internos, para reconstrução de defeitos complexos em cabeça e pescoço. MÉTODO: Retalhos osteomiocutâneos contendo 6ª e 7ª costelas e músculo reto abdominal foram dissecados bilateralmente em 35 cadáveres, 26 do sexo masculino e 9 do sexo feminino. Estudou-se a vascularização cutânea do abdome superior pelas perfurantes da artéria epigástrica superior superficial (SSEA); e os padrões de vascularização do 6º e 7º arcos costais e músculo reto abdominal a partir dos vasos torácicos internos, musculofrênicos e intercostais. O arco de rotação para segmento cefálico com ponto pivô na margem inferior da primeira costela foi avaliado. RESULTADOS: Foram dissecadas 114 perfurantes SSEA, 62 à direita e 52 à esquerda, com calibre arterial médio homogêneo de 0,68 mm. A maior frequência de perfurantes encontradas foi no grupo de 0,5 a 1,0 mm, com 60 (52,7%) ocorrências. Não houve diferença estatisticamente significativa para localização e calibre em relação ao lado. Também não houve correlação dos calibres com localização, idade, peso e altura dos cadáveres. Sessenta e dois retalhos osteomiocutâneos com pedículo nos vasos torácicos internos, 6° e 7° arcos costais e músculo reto abdominal foram divididos em 3 tipos de acordo com o padrão de vascularização do sexto arco costal. O tipo 1, em que a vascularização da sexta costela é pela artéria musculofrênica, foi o mais frequente, com 46 (74,2%) ocorrências. Dez pedículos vasculares diferentes para os componentes do retalho foram individualizados e medidos bilateralmente. Apenas quatro foram significativamente maiores nos homens e, dois, maiores à direita. Os calibres de todos os pedículos arteriais foram homogêneos em relação ao sexo e ao lado. O comprimento do pedículo para o componente ósseo do retalho variou de 18,5 a 21,6 cm, alcançando mandíbula e maxila em todos as dissecações. Já o componente miocutâneo do reto abdominal atingiu occipício em todos os casos e levou os vasos epigástricos profundos inferiores para possível anastomose vascular. Cinco pacientes foram operados em 2 anos com adequada integração dos retalhos e recuperação do contorno e função mandibulares. CONCLUSÃO: Em todas as dissecações de cadáver as perfurantes SSEA estiveram presentes bilateralmente com calibre maior que 0,3 mm; os retalhos osteomiocutâneos pediculados nos vasos torácicos internos foram constantes e alcançaram o segmento cefálico. Os pacientes operados recuperaram forma e função mandibulares. Este retalho pode ser uma alternativa para reconstruções secundárias em cabeça e pescoço<br>INTRODUCTION: The use of combined well-vascularized flaps offers better results and rehabilitation for complex head and neck defects. Microsurgical reconstructions are the gold standard. However, there are patients with vessel-depleted necks from multiple recurrences and resections, failed reconstructions, neck dissections, infections, fistulas and radiotherapy, which impair adequate free tissue transfers. With better oncologic therapies, these patients have become more common and lack reconstructive options. OBJECT: To describe a combined ostemyocutaneous pedicled flap based on the internal mammary artery for complex head and neck reconstructions. METHOD: Osteomyocutaneous flaps with 6th and 7th ribs and the rectus abdominis muscle were dissected bilaterally on 35 cadavers, 26 male and 9 female. We studied the upper abdominal irrigation through isolation of the superficial superior epigastric artery perforators (SSEA) and the vascular pedicles to the 6th and 7th ribs, and the rectus abdominis muscle arising from the internal mammary, the musculophrenic and the intercostal arteries. The arc of rotation of the flap to the cephalic segment was tested with the pivot point on the lower margin of the first rib. RESULTS: We dissected 114 SSEA, 62 on the right side and 52 on the left. They had an homogeneous mean arterial diameter of 0,68 mm. Sixty perforators (52,7%) were on the group that ranged from 0,5 to 1,0 mm. After statistical analysis, there were no differences in relation to the side as for location and caliber of the perforators. Neither there was any relation of the arterial calibers to the location, age, weight and height of the cadavers. Sixty-two internal mammary artery pedicled osteomyocutaneous flaps, that carried the 6th and 7th ribs and the rectus abdominis muscle, were divided in 3 types depending on the vascular pattern to the 6th costal arch. Type 1, where the pedicle to the 6th rib branches from the musculophrenic artery, was the most frequent and dissected in 46 flaps (74,2%). Ten different vascular pedicles to the components of the flap were isolated and measured bilaterally. Only four of them were significantly longer in males and, two, were longer on the right side. The arterial diameters were also homogeneous in relation to the side and sex. The pedicle length to the osseous component of the flap varied from 18,5 to 21,6 cm, which allowed to reach mandible and maxilla in all dissections. The myocutaneous component of the rectus abdominis muscle reached the occipitum in all cases and carried along the deep inferior epigastric vessels for vascular anastomosis if needed. Five patients were operated in 2 years with adequate flap integration and recovery of the mandible contour and function. CONCLUSION: In all cadaveric dissections SSEA perforators were bilaterally present with a caliber bigger than 0,3 mm; internal mammary artery osteomyocutaneous pedicled flaps were constant and reached the cephalic segment. The operated patients recovered mandibular form and function. This flap can be an alternative for secondary head and neck reconstructions

La tomographie par émission de positons (TEP) est une modalité d’imagerie nucléaire qui possède une place de choix dans la démarche diagnostique des démences neuro-dégénératives. Le traceur radiopharmaceutique le plus utilisé, le 18F-FDG, permet d’obtenir une cartographie volumique du métabolisme cérébral. L’argument scintigraphique de démence repose sur la mise en lumière d’un hypo-métabolisme relatif d’une région d’intérêt (ROI) particulière par rapport à une autre, habituellement son symétrique controlatéral. Certains cas d’étude sont cependant très difficiles à interpréter à l’oeil nu, principalement à un stade précoce d’évolution de la maladie. Jusqu’à présent, le développement d’outils (semi-)automatiques de comparaison directe de ROIs s’est vu limité par la méconnaissance de la statistique que suivent les données reconstruites ; les principales méthodes déjà mises au point préférant alors utiliser d’imposantes bases de données pour évaluer la reconstruction à analyser à travers un score de dissimilarité par rapport à un groupe de contrôles. Dans cette thèse, nous proposons une nouvelle méthodologie entièrement intégrée allant de la reconstruction d’images d’activité à l’aide au diagnostic de démences. Basée sur la reconstruction d’intervalles de confiance, l’approche proposée permet 1/ d’accéder directement à une information sur la variabilité statistique des données, 2/ de reconstruire des images qualitativement et quantitativement probantes pour faciliter la lecture de l’examen par le médecin nucléaire, 3/ de fournir un score de risque du patient d’être atteint de démence neuro-dégénérative. Les résultats obtenus avec cette dernière sont comparables avec des outils validés en routine clinique, sans nécessiter aucune autre information que les seules données d’acquisiton TEP<br>Positron emission tomography (PET) is a nuclear imaging modality that has a prominent place in the neurodegenerative dementias diagnosis. After a reconstruction step, the most widely used radiopharmaceutical tracer, the 18F-FDG, provides a volume mapping of brain metabolism. The scintigraphic argument for dementia is based on the finding of a relative hypo-metabolism of one particular region of interest (ROI) to another, usually its contralateral symmetric. However, some case studies are very difficult to interpret with the naked eye, mainly at an early stage of the disease’s development. Until now, the development of (semi-)automatic tools for direct comparison of ROIs has been limited by the lack of statistical knowledge of the reconstructed data ; the main methods already developed preferring to use large databases to evaluate the reconstruction through a dissimilarity score compared to a group of control patients. In this thesis, we propose a new, fully integrated methodology, from reconstruction to assistance in the diagnosis of dementia. Based on the reconstruction of confidence intervals, the proposed approach allows 1/ direct access to information on the statistical variability of the data, 2/ reconstruction of qualitatively and quantitatively convincing images to facilitate the reading of the examination by the physician, 3/ provision of a risk score for the patient to be affected by a neurodegenerative dementia. The results obtained with the latter are comparable with tools validated in clinical routine, except that this method does not require any other information than PET acquisition data itself

L'utilisation d'algorithmes itératifs est aujourd'hui largement répandue dans tous les domaines du traitement du signal et des communications numériques. Dans les systèmes de communications modernes, les algorithmes itératifs sont utilisés dans le décodage des codes ''low-density parity-check'' (LDPC), qui sont une classe de codes correcteurs d'erreurs utilisés pour leurs performances exceptionnelles en terme de taux d'erreur. Dans un domaine plus récent qu'est le ''compressed sensing'', les algorithmes itératifs sont utilisés comme méthode de reconstruction afin de recouvrer un signal ''sparse'' à partir d'un ensemble d'équations linéaires, appelées observations. Cette thèse traite principalement du développement d'algorithmes itératifs à faible complexité pour les deux domaines mentionnés précédemment, à savoir le design d'algorithmes de décodage à faible complexité pour les codes LDPC, et le développement et l'analyse d'un algorithme de reconstruction à faible complexité, appelé ''Interval-Passing Algorithm (IPA)'', dans le cadre du ''compressed sensing''.Dans la première partie de cette thèse, nous traitons le cas des algorithmes de décodage des codes LDPC. Il est maintenu bien connu que les codes LDPC présentent un phénomène dit de ''plancher d'erreur'' en raison des échecs de décodage des algorithmes de décodage traditionnels du types propagation de croyances, et ce en dépit de leurs excellentes performances de décodage. Récemment, une nouvelle classe de décodeurs à faible complexité, appelés ''finite alphabet iterative decoders (FAIDs)'' ayant de meilleures performances dans la zone de plancher d'erreur, a été proposée. Dans ce manuscrit nous nous concentrons sur le problème de la sélection de bons décodeurs FAID pour le cas de codes LDPC ayant un poids colonne de 3 et le cas du canal binaire symétrique. Les méthodes traditionnelles pour la sélection des décodeurs s'appuient sur des techniques asymptotiques telles que l'évolution de densité, mais qui ne garantit en rien de bonnes performances sur un code de longueurs finies surtout dans la région de plancher d'erreur. C'est pourquoi nous proposons ici une méthode de sélection qui se base sur la connaissance des topologies néfastes au décodage pouvant être présente dans un code en utilisant le concept de ''trapping sets bruités''. Des résultats de simulation sur différents codes montrent que les décodeurs FAID sélectionnés grâce à cette méthode présentent de meilleures performance dans la zone de plancher d'erreur comparé au décodeur à propagation de croyances.Dans un second temps, nous traitons le sujet des algorithmes de reconstruction itératifs pour le compressed sensing. Des algorithmes itératifs ont été proposés pour ce domaine afin de réduire la complexité induite de la reconstruction par ''linear programming''. Dans cette thèse nous avons modifié et analysé un algorithme de reconstruction à faible complexité dénommé IPA utilisant les matrices creuses comme matrices de mesures. Parallèlement aux travaux réalisés dans la littérature dans la théorie du codage, nous analysons les échecs de reconstruction de l'IPA et établissons le lien entre les ''stopping sets'' de la représentation binaire des matrices de mesure creuses. Les performances de l'IPA en font un bon compromis entre la complexité de la reconstruction sous contrainte de minimisation de la norme $ell_1$ et le très simple algorithme dit de vérification.

The design and evaluation of computer systems rely heavily upon simulation. Simulation is also a major bottleneck in the iterative design process. Applications that may be executed natively on physical systems in a matter of minutes may take weeks or months to simulate. As designs incorporate increasingly higher numbers of processor cores, it is expected the times required to simulate future systems will become an even greater issue. Simulation exhibits a tradeoff between speed and accuracy. By basing experimental procedures upon known statistical methods, the simulation of systems may be dramatically accelerated while retaining reliable methods to estimate error. This thesis focuses on the acceleration of simulation through statistical processes. The first two techniques discussed in this thesis focus on accelerating single-threaded simulation via cluster sampling. Cluster sampling extracts multiple groups of contiguous population elements to form a sample. This thesis introduces techniques to reduce sampling and non-sampling bias components, which must be reduced for sample measurements to be reliable. Non-sampling bias is reduced through the Reverse State Reconstruction algorithm, which removes ineffectual instructions from the skipped instruction stream between simulated clusters. Sampling bias is reduced via the Single Pass Sampling Regimen Design Process, which guides the user towards selected representative sampling regimens. Unfortunately, the extension of cluster sampling to include multi-threaded architectures is non-trivial and raises many interesting challenges. Overcoming these challenges will be discussed. This thesis also introduces thread skew, a useful metric that quantitatively measures the non-sampling bias associated with divergent thread progressions at the beginning of a sampling unit. Finally, the Barrier Interval Simulation method is discussed as a technique to dramatically decrease the simulation times of certain classes of multi-threaded programs. It segments a program into discrete intervals, separated by barriers, which are leveraged to avoid many of the challenges that prevent multi-threaded sampling.

Ce travail de thèse, inclus dans un projet structurant plus vaste, projet SIMOVI (SImulation des MOuvements du VIsage), s’attache à étudier spécifiquement la mimique faciale en corrélant les déplacements visibles du revêtement cutané et les mouvements musculaires internes à travers le développement de plusieurs méthodologies. L’ensemble de la mimique faciale ne pouvant être étudié, étant donné la multitude d’expressions, les mouvements pertinents à étudier dans nos travaux ont été identifiés. Ces mouvements ont été caractérisés chez 23 sujets jeunes dans une analyse descriptive qualitative et clinique, basée sur une méthodologie s’appuyant sur l’analyse d’enregistrements vidéoscopiques, et le développement d’un codage issu du FACS (Facial Action Coding System). Une cohorte de référence a ainsi été constituée. Après avoir validé notre méthodologie pour la caractérisation externe de la mimique, l’analyse des muscles peauciers par l’IRM a été réalisée sur 10 hémifaces parmi les sujets sains issus de la cohorte. Cette caractérisation a fait appel, à partir d’une anatomie in vivo, à une modélisation de certains muscles peauciers (zygomaticus major en particulier) afin d’extraire des paramètres morphologiques, de réaliser une analyse plus fine de la morphologie musculaire en 3 dimensions, et d’apporter une meilleure compréhension du comportement cinématique du muscle dans différentes positions. Par son intégration dans un questionnement plus vaste :- comment caractériser objectivement la mimique faciale ? - quels sont les indicateurs qualitatifs et quantitatifs de la mimique que nous pouvons recueillir, et comment réaliser ce recueil ? - comment utiliser les développements technologiques dans les applications cliniques ? Ce travail constitue une étape préliminaire à d’autres travaux. Il pourra fournir des données de référence à des fins de modélisation, de simulation de la mimique faciale, ou de développements d’outil de mesures pour le suivi et l’évaluation des déficits de la mimique faciale<br>The aim of this research is to study facials mimics movements and to correlate externat soft tissue (i.e., cutaneous) movement during facial mimics with internal (i.e., facial mimic muscle) movement. The entire facial mimicry couldn't be studied, that's why relevant movements had been selected. Those movements were characterised by a clinically qualitative analysis in 23 young healthy volunteers. The analysis was performed with video recordings including scaling derived from the FACS (Facial Action Coding System). After the validation of external characterisation by this method, internal characterisation of the mimic facial muscle was carried out in 10 volunteers. A modelization of selected facial mimic muscle as Zygomaticus Major was achieved. With this work, morphological parameters could be extracted, 3D morphometric data were analysed to provide a better understanding of cinematic behaviour of muscle in different positions.This research is included in the Simovi Project, which aims to determine to what extent a facial mimic can be evaluated objectively, to select the qualitative and quantitative indicators for evaluation of mimic facial disorders, and to transfer our technological developments in clinical field. This research is a first step and provides data for simulation or developments of measurement tools in evaluation and follow-up of mimic facial disorders

I detta examensarbete har tidsstämplar extraherats ur ett forensiskt perspektiv från ett hemautomationssystem med styrenheten Homey från Athom. Först konstruerades ett fiktivt händelsescenario gällande ett inbrott i en lägenhet med ett hemautomationssystem. Hemautomationssystemet bestod av flera perifera enheter som använde olika trådlösa nätverksprotokoll. Enheterna triggades under händelsescenariot. Därefter testades olika metoder för att få ut data i form av tidsstämplar. De metoder som testades var rest-API, UART och chip-off på flashminnet medan JTAG inte hanns med på grund av tidsbrist. Den metod som gav bäst resultat var rest-API:t som möjliggjorde extrahering av alla tidsstämplar samt information om alla enheter. I flashminnet hittades alla tidsstämplar, men det var inte möjligt att koppla ihop dessa tidsstämplar med en specifik enhet utan att använda information från rest-API:t. Trots att rest-API:t gav bäst resultat så var det den metod som krävde en mängd förutsättningar i form av bland annat inloggningsuppgifter eller en rootad mobil. Med hjälp av de extraherade tidsstämplarna rekonstruerades sedan händelsescenariot för inbrottet.<br>The purpose of this bachelor thesis was to extract timestamps from a home automation system with a control unit named Homey in a forensic perspective. The first step was to create a course of event regarding a burglar breaking into an apartment with home automation. The home automation system consisted of some peripheral units using different types of wireless network protocols. All these units were triggered during the break in. Thereafter different types of methods were tested in an attempt to extract the timestamps for each unit. These methods included rest-API, UART and chip-off on a flash memory. The method using JTAG were not tested due to lack of time. Rest-API was the method that provided most information about the units and time stamps. The flash memory also contained every timestamp, however it did not provide any information about which timestamp belonged to which unit. Even though the rest-API was the best method to extract data, it was also the method with most requirements such as credentials or a rooted smartphone. With the extracted timestamps it was possible to reconstruct the course of events of the break-in.

De nombreuses applications de communications numériques font face à des canaux de transmission sélectifs en temps et en fréquence que nous pouvons assimiler à des systèmes linéaires variants dans le temps. À travers ces travaux de thèse, nous montrons que les modulations multiporteuses suréchantillonnées constituent une technique de transmission adaptée à ce type d'environnement. Cependant, la complexité algorithmique des émetteurs-récepteurs présente un frein majeur à leur adoption. Fort de ce constat, nous nous intéressons à la sous-famille des modulations multiporteuses suréchantillonnées à filtres courts (WCP-OFDM), dont la complexité algorithmique est comparable à celle de l'OFDM avec préfixe cyclique. Après avoir exprimé les conditions de reconstruction parfaite, nous développons des égaliseurs de faible complexité et étudions la problématique du rapport de puissance crête sur puissance moyenne du signal en sortie d'émetteur. Enfin, nous analysons les performances de ces modulations à travers plusieurs scénarios de propagation radiomobile. Les résultats de simulation confirment l'intérêt du WCP-OFDM, associé à des filtres prototypes bien localisés en temps et en fréquence pour faire face aux canaux doublement sélectifs.

I investigate the depths of memory, the entanglement of personal recollections with communal knowledge (learned semantic information from media and society such as facts and social norms) and the changing perceptions of environments over time. Memories define us. Throughout life we are exposed to vast quantities of imagery through a variety of media and personal experiences. Over time our firsthand experiences and what we witness in film, print, photography, and the internet become indistinguishable in our memory. My work recreates consequential scenes from my past through technical drawings and blended imagery while exploring the possibilities provided by the interaction of common knowledge and the ambiguous nature of memory.<br>M.F.A.<br>Masters<br>Visual Arts and Design<br>Arts and Humanities<br>Emerging Media; Studio Art and the Computer Track

The verb in a Chatino language bears a value for Aspect (a grammatical category of Zapotecan verbs which indicates a bundle of aspectual and modal features), marked with a prefix, a tonal change, or both. There is a moderate amount of allomorphy among the Aspect prefixes, and when verbs of Tataltepec Chatino are grouped according to in which particular forms a given verb’s Aspect prefix appears, generalizations about the verbs can be made. For example, verbs with one set of allomorphs are are generally transitive; verbs with another set are generally intransitive, and so on. Attempts to meaningfully classify the verbs of contemporary Tataltepec Chatino are complicated by the effects of a few incomplete processes, such as the syncopation of historically disyllabic roots. To overcome this difficulty, a more conservative form of Tataltepec Chatino was constructed from an analysis of the lexical entries of a bilingual dictionary published in 1970 and from my own field notes. This pre-1970 Tataltepec Chatino shows the Aspect prefixes quite clearly and allows for a ready classification of the verbs. When the verb classes which can be identified for Tataltepec Chatino are compared to those found for other Chatino languages, we can see the development of several subclasses being brought about by various morphophonemic processes, such as the syncopation of Aspect prefix vowels, the deletion of similar consonants, and the merger of coronal and velar stops before laterals. This verb classification also corroborates those undertaken for Zenzontepec Chatino and the Eastern Chatino of San Marcos Zacatepec, as this verb classification scheme is largely in concord with them or if not, convincing explanations of Tataltepec Chatino’s deviance can be found.<br>text

This study explored the perceptions of beneficiaries of the Reconstruction and Development Programme (RDP) with regard to the role that RDP houses play socially, psychologically, and physically in the lives of occupants after moving from an informal settlement into RDP houses. Given that the said housing programme targets disadvantaged people, it was important to understand their own perceptions of these houses. The study also explored the perceptions of government officials in regard to their experiences relating to RDP houses. A case study approach was adopted and Bronfenbrenner‟s ecological theory of human development was used as the theoretical framework to guide this study. Data were collected through semi-structured interviews with two groups of participants. First, Group A comprised three RDP participants who lived in an informal settlement before relocation to their RDP houses. Second, Group B comprised three participants from the national, provincial and local offices of the governmental human settlements departments respectively. Data were analysed and four main themes as well as the subthemes emerged from the analysis. The four main themes are the bolstered sense of psychological well-being; access to basic services, amenities, and benefits of an improved infrastructure; pride of ownership; and ownership as a form of personal economic development or empowerment. Findings suggested that the participants reflected expressions of joy, a sense of permanence, a feeling of being home, hope for the future, and an absence of worry. These meanings and interpretation of home ownership reflect how the participants identify with their RDP houses and how pleased they are to own a house. Basic services enhance their overall quality of life in relation to their psychological, physical and social well-being. Interestingly, access to socio-economic services and amenities such as connected water and electricity inside The Experience of Moving from an Informal Settlement to a Secure Stable Home 4 the houses, the availability of schools and clinics, transport services, and a habitable environment, were found to play an important role in the lives of the participants. However, factors which hamper the success of RDP housing and compound the hopelessness of living in an informal settlement as well as the problems that RDP home owners encounter, which restrain their pride of ownership are: ambivalence over restrictions or limitations imposed by building regulations, the size of the houses, the poor quality construction, and envy at improvements made to subsequent RDP houses. In conclusion, the findings add to a greater theoretical understanding of the factors contributing to human development and the factors that impede the effectiveness of the housing programme. These factors draw attention to a number of important issues regarding RDP housing, which may assist housing practitioners, and in particular, policy developers, in developing policy that may be more useful in meeting the needs of the people. This could enhance the existing housing programme as well as alert the housing practitioners to existing shortcomings and offer them the opportunity to become acquainted therewith. These factors that impede RDP ownership suggest a need for the government and other relevant stakeholders to engage in the issues that prevent the successful implementation of the housing programme thereby maximising the effectiveness of the housing programme, primarily in order to strive to improve the lives of previously disadvantaged people.<br>Social Work<br>MA SS (Psychology)

Rock glaciers are dynamic landforms and, as such, exhibit interesting and welldeveloped structural features, which translate to surface morphology in the form of ridges and furrows. These distinguishing features have led researchers to study the physics behind the movement and internal deformation of rock glaciers. For years researchers had no access to the internal makeup of rock glaciers. Thus, proposed models and discussion have been based on theoretical concepts of electromagnetic (EM) wave propogation. With the application of ground penetrating radar (GPR) to provide a view of the interior structure of a rock glacier, researchers had “real” data to verify their models. However, no comparison has been made between a GPR profile and an actual cross-section of a rock glacier. The purpose of this thesis is to validate the fidelity of GPR in showing the actual structure of a rock glacier. A trench that was excavated through the toe of a rock glacier on Mount Mestas in south central Colorado provided a view of the actual structure of the landform. The structure in the trench was compared with GPR and EM data. The GPR study was conducted using a PulsEKKOTM 100A subsurface imaging radar with 25, 50, and 100 MHz antennas, to detect dielectric contrasts within the rock glacier. A frequency domain EM34 by Geonics LtdTM was also used to supplement the GPR data by measuring the rock glacier’s conductivity at various depths. This thesis proved, by utilizing statistics, that GPR is a useful tool in visualizing the interior structure of rock glaciers. The 100 MHz antennas clearly show small scale reflection horizons caused by changes in clast orientation and subsurface material composition. These events coincide with structures seen in the trench. Individual clasts greater than 0.375 m were also recognized as point sources in the GPR profiles. Large continuous bedding layers were observed with the 25 and 50 MHz antennas, which reflect the structure seen in the trench. A large scale thrust fault was also located with the GPR. However, this was not visible in the panoramic photograph because the fault occurs below the base of the trench.

Modern society frequently fails to achieve the goal of improved rationality and this is largely because the conditions for ideal speech do not prevail. We do not always permit everyone an equal opportunity to explain their point of view and the force of the best argument does not always prevail. Communication becomes more difficult when people cannot meet face to face, but it is also hindered when people cannot contact one another easily. There is, therefore, a trade-off between using computer-mediated media for communication and speaking to each other in person. Although meaning can never be shared to the extent that two individuals have precisely the same interpretation of a concept, and society is not based on individuals uniformly embracing identical views or values, in every day life consensus needs to be reached and truth claims, normative validity claims and aesthetic validity claims must be made, debated and eventually accepted or refuted. Collaboration on substantial tasks that require the development of concepts and reconstruction of meaning depends on effective communication. In the distributed social structures which have developed as a result of globalisation it is important that dispersed teams are able to work together. This includes collaborative learning in distance education. In the action research undertaken first year Informatics students could choose between doing team work face-to-face, or as dispersed teams communicating via e-mail or WebCT. The discussions were recorded and were analysed to identify the different types of communicative action engaged in. This was done to understand how this group collaborate so that success factors could be identified and proposals be made regarding education in the use of e-mail. It was found that the virtual (dispersed) teams studied did not succeed in collaborating. Communication ability is defined in this thesis as the skill that compensates for the inherent leanness of the medium used. A number of depictions of factors contributing to successful asynchronous collaboration are provided. Different classes of information and time, trust and communication ability assist in constructing meaning when text is communicated electronically. This led to suggestions regarding improving the communications ability of individuals.<br>Dissertation (PhD (Information Technology))--University of Pretoria, 2003.<br>Informatics<br>unrestricted

The ribosome is a macromolecular machine, present in high copy number in the cell, that synthesizes proteins from information encoded in messenger RNA. It is a universal translator, found in all life forms and in all eras recent enough to bear life. The ribosome is structurally complex and its structure is highly evolutionarily conserved; that conservation reinforces the concept that its function in executing translation is essential. As a subject of study, the ribosome lends itself well to direct imaging, as it is large, asymmetric, dynamic, and it interacts with other heterogeneous agents throughout the translation process; if we are to infer function from structure, then the most certain way to observe the ribosome’s structure is to image it as directly as possible. Cryo-electron microscopy and single particle reconstruction are appropriate tools for this endeavor, as they can produce high-resolution three-dimensional structures of ribosomes or other macromolecular samples, and they can even reveal multiple biologically relevant states of a single sample. Although the ribosome is highly conserved in terms of its presence and core structure and functions, there is considerable variation among taxa, and the function of some of this variation is not yet understood. For example, the ribosome of the unicellular trypanosomatid parasite Leishmania major exhibits unusually large expansion segments of ribosomal RNA, as well as unusual cleavage sites in ribosomal RNA that is otherwise conserved. Here, we present a three-dimensional cryo-electron microscopy reconstruction of the 80S ribosome of Leishmania major and compare it to the available ribosome structures of closely related parasites. There is also structural variation related to the mechanism of translation: certain viruses with RNA genomes employ highly structured segments of RNA called internal ribosome entry sites to initiate translation of viral proteins on host cell ribosomes via noncanonical mechanisms. We explore one instance of this with a reconstruction of the encephalomyocarditis virus internal ribosome entry site bound with necessary protein factors to a eukaryotic 40S ribosomal subunit.