Submitted by Maria Aparecida (cidazen@gmail.com) on 2017-09-06T13:31:47Z No. of bitstreams: 1 Antonio_José_da_Silva2.pdf: 2564341 bytes, checksum: ff7454362aecf3bf6afd177edfd5c821 (MD5) / Made available in DSpace on 2017-09-06T13:31:47Z (GMT). No. of bitstreams: 1 Antonio_José_da_Silva2.pdf: 2564341 bytes, checksum: ff7454362aecf3bf6afd177edfd5c821 (MD5) Previous issue date: 2009-06-05 / FAPEMA / The Anode effect that occurs in electrolytic smelter pot is responsible for gases such as PFC s. These gases contribute to the greenhouse effect, and in addition jeopardizes its productive capacity. From the voltage (output) and current (input) are estimate ARX and OE models of the electrolytic smelter pot using the Systems Identification Theory, the ARX and OE models of the electrolytic smelter pot are built to represent the steady state operation and the anode effect occurrence. After the simulation are chosen the models with better adjustment to the measure exit. For the selection are used established criteria along the research, the ARX and OE models of electrolytic smelter pot, are built to represent the full state operation of the electrolytic smelter pot. Based on real data and via algebraic properties, the models generate the functions of specific transfer of each model that are validated with real data obtained in the industry, the answer in time, in the convergence frequency and speed are analyzed. From the transfer function is made the representation of the normal stage of operation of the electrolytic smelter pot, and by the properties of the estimate model is made the prediction the anode effect identifying the increase of the voltage in the validation stage. Therefore, this work introduces the investigation of ARX and OE parametric models how better represent the operation of the electrolytic smelter pot to can enable the prediction of the anode effect in the productive process of the aluminum. In this dissertation, we propose the models development in the domain of the continuous and discreet time with a study of her transitory answers and of steady state as well as your answer in frequency of your normal operation and in the phase that precedes the anode effect. / O efeito anódico que ocorre nas cubas eletrolíticas é responsável pela emissão de gases como os PFC s, gases esses, que contribuem para o efeito estufa, além de comprometer sua capacidade produtiva. A partir dos sinais de tensão (saída) e corrente (entrada) são estimados modelos ARX e OE da cuba eletrolítica utilizando a Teoria de Identificação de Sistemas. Após a simulação são escolhidos os modelos com melhor ajuste à saída medida. Para a seleção são utilizados critérios estabelecidos ao longo da pesquisa. Os modelos ARX e OE das cubas eletrolítica, são construídos para representar o pleno estado de funcionamento da cuba. Baseados em dados reais e via propriedades algébricas, os modelos geram as funções de transferência específicas de cada modelo que são validadas com dados reais obtidos na indústria, a resposta no tempo, na freqüência e velocidade de convergência são analisadas. A partir da função de transferência é feita a representação da fase normal de funcionamento da cuba eletrolítica, e pelas propriedades do modelo é feita a predição do efeito anódico identificando o aumento da tensão na fase de validação. Portanto, este trabalho apresenta a investigação de modelos paramétricos ARX e OE que melhor representam o funcionamento da cuba eletrolítica para possibilitar a predição do efeito anódico no processo produtivo do alumínio. Nesta dissertação propomos o desenvolvimento de modelos no domínio do tempo contínuo e discreto com um estudo das suas respostas transitória e de regime permanente assim como sua resposta em freqüência de seu funcionamento normal e na fase que antecede o efeito anódico.

近年來由於亞洲金融風暴的肆虐，產生經濟不景氣，使得失業的問題逐漸受到社會所關注，本論文企圖以三個時間序列方法：1.單變量ARIMA模型；2.轉換函數(TF)模型；3.向量自迴歸(VAR)模型來建立台灣地區的失業率時間序列預測模型。資料則是利用台灣地區民國75年1月至民國87年12月的失業率月資料作實證預測分析，為了知道資料是否來自時間趨勢模型，測試是否經過差分消掉一部份的記憶會發生預測的誤差，所以先以多步(multi-step)預測和一步(one-step)預測的方法計算出民國88年1月至88年12月預測值，而預測評估準則則採用(1)MAPE、RMSPE、MPE及泰爾不等係數(THEIL)；(2)變化方向誤差與趨勢變化誤差兩大方向來做預測比較。最後將算出的12期預測值與行政院主計處整體統計資料庫中所得到的失業率實際值利用預測評估準則做比較，結果發現一步預測法較多步預測法準確；而向量自迴歸模型(VAR)在大部份的預測期數上有較小的MAPE、RMSPE、MPE及THEIL值，因為此VAR模型考慮了在變數之間的共整合現象，有助於模型的預測，所以有較好預測的能力；反而是較複雜的ARIMA模型及轉換模型預測能力稍差一點。 / In this thesis, we plan to construct three time series models to forecast the Taiwan unemployment Rate. These time series models are ARIMA model、transfer function (TF) model and Vector Autoregressive (VAR) model. The data set consists of monthly observations for the period 75:1-87:12 for unemployment rate. We want to know if the data came from time trend model. First, we use multi-step forecasting and one-step forecasting to calculate 12 forecasted values from 88:01-88:12. Then We compare the prediction performance of these two methods by using：(1) MAPE、RMSPE、MPE and Theil’s Inequality Coefficient (THEIL)；(2) Direction of Change Error and trend Change Error etc. It is found that one-step forecasting is more correct than multi-step forecasting and the forecasting performance of VAR model is improved by explicitly taking account of cointegration between the variables in the model，so VAR model has lower MAPE、RMSPE、MPE and THEIL for most horizons. However，the more parsimonious ARIMA and transfer function models have higher MAPE、RMSPE、MPE for most horizons.

Nous avons développé, et évalué en détail, un nouveau prototype d'inclinomètre longue base à niveaux hydrostatiques appelé " wth2o ". Ce système, aux principes particulièrement simples grâce à l'absence de pièces mécaniques mobiles, présente une grande fiabilité et une excellente stabilité (dérive linéaire de 0.05 µrad par mois). Sa haute résolution jusque dans la gamme des ondes sismiques longues périodes (où, par exemple, la résolution est meilleure que 0.001 masec, soit 5. 10-12 rad), et son niveau de bruit très bas, ont permis d'obtenir des résultats d'analyses harmoniques de marées terrestres (5 ans d'enregistrements) en excellent accord avec les modèles, et dont les écarts quadratiques moyens sont les plus bas de toutes les mesures inclinométriques réalisées au Laboratoire de Géodynamique de Walferdange (Luxembourg). A titre d'exemple, l'amplitude de l'onde M2 est déterminée avec une incertitude de seulement 0.003 masec, tandis que sa phase est déterminée avec un EQM de 0.028°, ce qui correspond à une incertitude de seulement 3.3 secondes. Cet instrument permit également d'observer des phénomènes rarement mesurés avec ce type d'appareil, tel les modes sphéroïdaux et toroïdaux les plus graves des oscillations libres de la Terre excitées par le séisme du Dénali (Mw 7.9) en novembre 2002, ou les passages successifs des ondes de Love jusqu'à G7, correspondant à 3 révolutions de ces ondes de surface autour du globe. Il fut également possible de séparer pour la première fois dans une analyse harmonique de marée terrestre inclinométrique, les constituants des groupes ter- et quater-diurnes. Ces très petites ondes enregistrées sont vraisemblablement liées aux ondes de marées océaniques propres aux eaux peu profondes présentes en Mer du Nord. Les modèles théoriques détaillés de cet appareil (comprenant des composantes relatives à l'amortissement produit par l'écoulement des fluides entre les électrodes des capteurs capacitifs) ont permis de dériver les solutions des équations du mouvement en composante inclinométrique et accélérométrique. De ces solutions furent tirées les formes théoriques des fonctions de transfert de l'appareil. Ces fonctions de transferts furent comparées avec succès aux mesures expérimentales de la réponse en fréquence. Grâce aux formes analytiques des fonctions de transfert en composante inclinométrique et accélérométrique qui sont données dans le présent travail, il est possible de calculer les caractéristiques géométriques optimales pour la construction d'un prototype devant répondre aux besoins particuliers d'une nouvelle application. Une étude originale des effets de ménisques (déformations de l'interface des fluides au contact de la paroi solide des pots) a montré que, s'ils n'ont pas d'influence sur les mesures en mode différentiel, ils peuvent par contre introduire des erreurs de plusieurs pour-cent sur l'estimation de la sensibilité par déplacement d'une quantité de liquide supposée connue. Cette erreur, ne dépendant que des propriétés physico-chimiques des fluides et matériaux en contacts, provient des variations de volumes de liquide contenu dans les ménisques lors des mouvements des interfaces. Si ces mouvements sont effectués lors des étalonnages sans que la ligne de contact ne se déplace, ces erreurs [en %] seront indépendantes du volume déplacé. Ces erreurs ne sont pas particulières à notre instrument mais peuvent affecter les étalonnages réalisés de la sorte pour tout inclinomètre à niveaux hydrostatiques, quel que soit le principe de mesure de l'instrument (mesures différentielles de pression, positionnement de flotteurs etc…). / We developed and evaluated a new prototype of long base water-tube tiltmeter named "wth2o". This system, particularly simple by the absence of moving parts, showed a great reliability and a fairly high stability (linear drift rate of 0.05 µrad/month). We analyzed a 5 years-long data set of Earth tides measurements performed in the Underground Laboratory for Geodynamics in Walferdange (Luxemburg). Its high resolution up to the long-period seismic band (where for instance the resolution is better than 0.001 masec, or 5. 10-12 rad) and its very low noise rate enabled us to obtain results in excellent accordance with the models, with the lowest root mean squares among all the results obtained with other tiltmeters in Walferdange. For instance, the amplitude of the M2 wave is estimated with a RMS as small as 0.003 masec and its phase is determined with an uncertainty below 0.028°, which represents 3.3 seconds only. With the "wth2o" we have also observed some events rarely measured with a water-tube, such as the gravest toroidal and spheroidal modes of the Earth free oscillations excited by the Mw 7.9 Denali earthquake or the successive passages of Love waves (up to G7) circling the globe. For the first time in an analysis of tilt Earth tide measurements, it was possible to separate the small constituents of the ter- and quater-diurnal band. The presence of these very small waves is most likely due to the effects of the shallow-water tides known to be remarkable in the North Sea. Theoretical models of this instrument (taking into account the damping produced by the liquids' flow between the plates of the capacitive sensors) allowed to obtain the solutions of the equations of motion for tilt as well as for acceleration. From these solutions we were able to produce very accurate theoretical transfer functions, as confirmed by the successful comparison with observed frequency responses. Thanks to the analytical tilt and acceleration transfer functions given in the present document it is possible to calculate the best geometrical characteristics for the construction of a new prototype having to respond to specific requirements of a new application. A new extended study of the menisci effects (deformations of the interface of the fluids in contact with the solid wall of the end vessels) showed that they do not influence the differential measurements but they could introduce errors of a few percents in the calibration factor when this factor is evaluated by the displacement of a "known" volume of liquid. This error depends only on the physical and chemical properties of the fluids and solids put in contact. It is due to the variation of volume of liquid trapped in the menisci while the interface is moving up- or downwards. If these interface movements are made without displacing the contact line, the errors [in %] will remain the same whatever the displaced volume of liquid could be. These errors can not only affect our results but can also be found in the calibration procedure of any kind of water-tube (central differential pressure, float positioned etc…).

Das Ziel der vorliegenden Arbeit ist die ausführliche Analyse und Beschreibung langfristiger abiotischer Standortbedingungen von Fluss und Grundwasser für das in einem Hartholzauenwald gelegene Untersuchungsgebiet im Naturschutzgebiet Saalberghau an der Mittleren Elbe bei Dessau. Hierzu erfolgt zunächst die Entwicklung eines allgemeinen Konzeptes, dass die Modellierung des Fluss- und des Grundwasserregimes sowie die statistische Auswertung dieser miteinander verbundenen Regime umfasst. Es wird davon ausgegangen, dass nur eine Synthese dieser Einzelbausteine die Grundlage für eine zusammenhängende Analyse und Beschreibung der komplexen auentypischen Dynamik dieser beiden Regime anhand objektivierbarer statistischer Parameter bilden kann. Darüberhinaus stellt die Zielsetzung auf langfristige Aussagen eine unentbehrliche Voraussetzung dar, um das Zeitspektrum der hier zu betrachtenden Altbäume typischer Hartholzauenbaumarten adäquat berücksichtigen zu können. / The present dissertation aims at a detailed analysis and description of the long-term abiotic site conditions (river flow and groundwater) for the floodplain area under investigation, namely a hardwood forest in the nature reserve "Saalberghau" on the Middle Elbe close to the town Dessau. For this purpose, firstly a general concept which covers the modelling of the surface water and groundwater regime as well as a statistical interpretation of these two interconnected regimes is developed. It is assumed that only a synthesis of those separate modules can form a sufficient basis for a cohering analysis and description of the complex dynamics of these two regimes in floodplain forests by means of objective statistic parameters. Furthermore, only longterm statements can take into account the age spectrum of the hardwood stand.

The main focus of this thesis is to analyse signals (signal-dependent analysis) and room responses (system-dependent analysis) from a statistical point of view, attempt to determine the underlying statistical relationships between the reverberant signals and the room responses and propose relevant statistical models. Based on such a statistical framework, this thesis aims to propose novel methodologies for the extraction of room acoustical information and parameters from reverberant signals. Schroeder's theory is experimentally evaluated for various Room Transfer Functions (RTFs) measured in many source/receiver positions in various enclosures and several related aspects are discussed. Using a statistical approach, the effects of reverberant energy on the histograms and statistical measures are discussed and models describing the relationship of statistical measures between the reverberant signal and the RTFs are extracted. Then, the statistical properties of Binaural Room Transfer Functions (BRTFs) and binaural cues are examined. The well-known property of the spectral standard deviation of the magnitude of RTFs, that is its convergence to 5.6 dB for diffuse fields, is examined for the case of BRTFs, using a similar approach and a generic model for the relationship of the spectral standard deviation of RTFs and BRTFs. This thesis is also concerned with the distance estimation problem from a perceptual and computational point of view. Two novel methods for the estimation of the source/receiver distance using speech signals are proposed. The first method is able to detect the distance between the speaker and the microphone in a room environment using single-channel signals. The distance-dependent variation of several temporal and spectral statistical features of single-channel signals is studied and a novel sound source distance detector, based on these features is developed. The second method estimates distance from binaural speech signals (two-channel signals). This method does not require a priori knowledge of the room impulse response, the reverberation time or any other acoustical parameter and relies on a set of novel features extracted from the reverberant binaural signals. For this method, a novel distance estimation feature is introduced exploiting the standard deviation of the difference of the magnitude spectra of the left and right binaural signals (termed here as Binaural Spectral Magnitude Difference Standard Deviation (BSMD STD)). Moreover, an extended and novel set of additional features based on the statistical properties of binaural cues (ILDs, ITDs, ICs) is extracted from an auditory front-end which models the peripheral processing of the human auditory system. Both methods rely on novel distance-dependent features, related to statistical parameters of speech signals. Finally, a novel method for the estimation of the direct-to-reverberant-ratio (DRR) from dual-channel microphone recordings without having knowledge of the source signal is presented. / Η παρούσα διατριβή ασχολείται με τη μελέτη και ανάλυση των στατιστικών χαρακτηριστικών ηχητικών σημάτων και των ακουστικών αποκρίσεων χώρου, έχοντας ως πρωταρχικό σκοπό να προτείνει σχέσεις που περιγράφουν τη συσχέτιση των στατιστικών χαρακτηριστικών των σημάτων με αντήχηση με τις ακουστικές αποκρίσεις χώρων. Βάσει ενός τέτοιου θεωρητικού πλαισίου, η διατριβή αυτή αποσκοπεί στο να προτείνει νέες μεθοδολογίες για την εξαγωγή πληροφορίας που σχετίζεται με τα ακουστικά χαρακτηριστικά των χώρων, κάνοντας χρήση ηχογραφημένων ηχητικών σημάτων (π.χ. σήματα ομιλίας) στους εκάστοτε κλειστούς χώρους. Το θεωρητικό υπόβαθρο αυτής της διατριβής βασίζεται σε υπάρχοντα θεωρητικά μοντέλα για το ηχητικό πεδίο μέσα σε ένα κλειστό χώρο, όπως, για παράδειγμα, το στατιστικό μοντέλο του Schroeder. Το μοντέλο του Schroeder επιβεβαιώνεται πειραματικά για ακουστικές αποκρίσεις που έχουν μετρηθεί σε διάφορες θέσεις, μέσα σε κλειστούς χώρους, οι οποίοι διαφέρουν στα ακουστικά χαρακτηριστικά τους. Βάσει στατιστικής ανάλυσης, εξάγονται στατιστικά μοντέλα, τα οποία περιγράφουν την επίδραση της αντήχησης στα ηχητικά σήματα, όταν αυτά αναπαραχθούν μέσα σε ένα κλειστό χώρο. Στη συνέχεια, λαμβάνοντας υπόψη αντιληπτικά μοντέλα ακοής, τα οποία προϋποθέτουν την ύπαρξη δυο ηχητικών σημάτων (δυο αυτιά, αμφιωτική ακοή) σε αυτή τη διατριβή, μελετώνται κάποιες παράμετροι οι οποίες εξάγονται από αμφιωτικές ακουστικές αποκρίσεις χώρου. Η ιδιότητα της φασματικής τυπικής απόκλισης συναρτήσεων μεταφοράς χώρων να συγκλίνει στην τιμή των 5.6~dB για διάχυτα ηχητικά πεδία, επεκτείνεται στην περίπτωση των αμφιωτικών αποκρίσεων χώρου και προτείνεται ένα γενικευμένο μοντέλο που συσχετίζει τη φασματική τυπική απόκλιση μονοφωνικών και αμφιωτικών συναρτήσεων μεταφοράς χώρου. Η διατριβή αυτή, επίσης, ασχολείται με το πρόβλημα της εκτίμησης της απόστασης μεταξύ πηγής και δέκτη. Προτείνονται δυο νέες μέθοδοι για την εκτίμηση της απόστασης μεταξύ πηγής και δέκτη, κάνοντας χρήση ηχητικών σημάτων ομιλίας. Η προτεινόμενη μέθοδος βασίζεται σε μια σειρά από στατιστικές παραμέτρους των οποίων οι τιμές μεταβάλλονται είτε στο πεδίο του χρόνου είτε στο πεδίο της συχνότητας. Η δεύτερη προτεινόμενη μέθοδος αφορά, επίσης, στην εκτίμηση της απόστασης πηγής/δέκτη, αλλά από αμφιωτικά σήματα. Η μέθοδος αυτή δεν προαπαιτεί γνώση της ακουστικής απόκρισης του χώρου, του χρόνου αντήχησης ή άλλης ακουστικής παραμέτρου και βασίζεται σε μια σειρά από νέες παραμέτρους, οι οποίες μπορούν να υπολογισθούν από τα αμφιωτικά σήματα με αντήχηση. Οι παράμετροι συνδυάζονται με δυο διαφορετικές τεχνικές αναγνώρισης προτύπων των οποίων τα μειονεκτήματα και πλεονεκτήματα συζητώνται. Στα πλαίσια αυτής της μεθόδου, προτείνεται μια νέα παράμετρος, η οποία βασίζεται στη διαφορά της φασματικής τυπικής απόκλισης του αριστερού και του δεξιού αμφιωτικού ηχητικού σήματος, η οποία αποδεικνύεται ότι σχετίζεται με τα στατιστικά της αντίστοιχης μονοφωνικής ακουστικής απόκρισης. Τέλος, προτείνεται μια σειρά από παραμέτρους οι οποίες βασίζονται στα στατιστικά χαρακτηριστικά αμφιωτικών παραμέτρων και σχετίζονται με το αντιληπτικό μοντέλο της ανθρώπινης ακοής. Τέλος, προτείνεται μια νέα μέθοδος για την εκτίμηση της στάθμης λόγου κατευθείαν προς ανακλώμενου ήχου από στερεοφωνικά σήματα.

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Gegenstand der vorliegenden Dissertation ist die Entwicklung von Kalibrierverfahren und Algorithmen zur Bildverarbeitung im Kontext von Multiprojektorsystemen mit dem Ziel, die Einsatzmöglichkeiten von derartigen Anlagen zu erweitern und die Nutzerakzeptanz solcher Systeme zu steigern. Die Arbeit konzentriert sich dabei insbesondere auf (annähernd) planare Mehrsegment-Projektionsanlagen, die aus preisgünstigen, nicht speziell für den Visualisierungbereich konzipierten Consumer- und Office-Projektoren aufgebaut werden. Im ersten Teil der Arbeit werden bestehende Verfahren zur geometrischen Kalibrierung, zum Edge-Blending sowie zur Helligkeits- und Farbanpassung auf ihre Eignung im Hinblick auf die Anforderungen untersucht und Erweiterungen entwickelt. Für die kamerabasierte Geometrie- Kalibrierung wird mit Lininenpattern gearbeitet, wobei ein effizienter rekursiver Algorithmus zur Berechnung der Schnittpunkte bei leicht gekrümmten Oberflächen vorgestellt wird. Für das Edge-Blending wird ein generalisiertes Modell entwickelt, das mehrere bestehende Ansätze kombiniert und erweitert. Die vorgenommene Modifikation der Distanzfunktion erlaubt insbesondere die bessere Steuerung des Helligkeitsverlaufs und ermöglicht weichere Übergänge an den Grenzen der Überlappungszonen. Es wird weiterhin gezeigt, dass das Edge-Blending mit bestehenden Ansätzen zum Ausgleich der Helligkeitsunterschiede wie Luminance Attenutation Maps kombiniert werden kann. Für die photometrische Kalibrierung ist die Kenntnis der Farb-Transferfunktion, also der Abbildung der Eingabe-Farbwerte auf die tatsächlich vom Projektor erzeugten Ausgaben, unerlässlich. Die herkömmlichen Ansätze betrachten dabei vorwiegend RGB-Projektoren, bei denen die dreidimensionale Transferfunktion in drei eindimensionale Funktionen für jeden Farbkanal zerlegt werden kann. Diese Annahme trifft jedoch auf die betrachteten Projektoren meist nicht zu. Insbesondere DLP-Projektoren mit Farbrad verfügen oft über zusätzliche Grundfarben, so dass der Farbraum deutlich von einem idealen RGB-Modell abweicht. In dieser Arbeit wird zunächst ein empirisches Modell einer Transferfunktion vorgestellt, das sich für derartige Projektoren besser eignet, allerdings die Helligkeit der Projektoren nicht vollständig ausnutzt. Im zweiten Teil der Arbeit wird ein kamerabasiertes Messverfahren entwickelt, mit dem direkt die dreidimensionale Farb-Transferfunktion ermittelt werden kann. Gegenüber bestehenden Verfahren werden tausende von Farbsamples gleichzeitig erfasst, so dass die erreichbare Sampledichte unter praxisrelevanten Messbedingungen von 17x17x17 auf 64x64x64 erhöht und damit die Qualität der photometrischen Kalibrierung signifikant gesteigert werden kann. Weiterhin wird ein Schnellverfahren entwickelt, dass die Messungsdauer bei 17x17x17 Samples von mehreren Stunden mit bisherigen Verfahren auf weniger als 30 Minuten reduziert. Im dritten Teil werden Algorithmen zur effizienten Bildverarbeitung entwickelt, die der GPU-basierten Anwendung der Kalibrierparameter auf die darzustellenden Bilddaten in Echtzeit dienen. Dabei werden die Möglichkeiten zur Vermeidung redundanter Berechnungsschritte beim Einsatz Stereoskopie-fähiger Projektoren ausgenutzt. Weiterhin wird das eigentliche Kalibrierverfahren effizient mit Verfahren zur Konvertierung von stereoskopischen Bildverfahren kombiniert. Es wird gezeigt, dass ein einzelner PC aus Standardkomponenten zur Ansteuerung einer Mehrsegment-Projektionsanlage mit bis zu 6 Projektoren ausreicht. Die Verwendung von DVI-Capture-Karten ermöglicht dabei den Betrieb einer solchen Anlage wie einen "großen Monitor" für beliebige Applikationen und Betriebssysteme.

This thesis presents a new optical imaging technique which measures the structure of objects without the use of lenses. Termed diffraction-contrast imaging (DCI), the method retrieves the object structure from a Fresnel diffraction pattern of the object, using a deconvolution algorithm. DCI is particularly adept at imaging highly transparent objects and this is demonstrated by retrieving the structure of an almost transparent cloud of laser-cooled atoms. Applied to transparent Bose-Einstein condensates, DCI should allow the non-destructive imaging of the condensate while requiring only the minimum possible apparatus of a light source and a detector. (For complete abstract open document)

O ganho crescen te de desempenho nos computadores modernos tem impulsionado os trabalhos científicos nas áreas de simulação computacional. Muitos autores utilizam em suas pesquisas ferramentas comerciais que limitam seus trabalhos ao esconder os algoritmos internos destas ferramentas e dificultam a adição de dados in-vivo nestes trabalhos. Este trabalho explora esta lacuna deixada por aqueles autores. Elaboramos um arcabouço computacional capaz de reproduzir os fenômenos óticos e fisiológicos do sistema visual. Construímos com superfícies quádricas os modelos esquemáticos do olho humano e propomos um algoritmo de traçado de raio realístico. Então realizamos um estudo nos modelos esquemáticos e a partir deles mais a adição de dados in-vivo obtidos de um topógrafo de córnea extraímos informações óticas destes modelos. Calculamos os coeficientes e Zernike dos modelos para tamanhos diversos de pupila e obtivemos medidas de aberração do olho humano. Os resultados encontrados estão de acordo com os trabalhos relacionados e as simulações com dados in-vivo estão consoantes com as produzidas por um aparelho de frente de onda comerciais. Este trabalho é um esforço em aproveitar as informações adquiridas pelos equipamentos modernos de oftalmologia, além de auxiliar o entendimento de sistemas visuais biológicos acabam também em auxiliar a elaboração de sistemas de visão artificial e os projetistas de sistemas óticos / The increase in performance of the modern computers has driven scientific work in the areas of computer simulation. Many authors use in their research commercial tools that use embedding algorithms, which sources are not provided, and it makes harder and sometimes impossible, the development of novel theories or experiments. This work explores this gap left for those authors. We present a computational framework capable to reproduce the optical and physiological phenomena of the human visual system. We construct schematical models of the human eye from quadrics surfaces and consider an algorithm of realistic ray tracing. Afterward, we performed a study on schematics models and in addition we introduce, in these models, in-vivo data obtained from corneal topography machine and extract optical information. We calculate the Zernike coefficients in the models for different sizes of pupil and measures of aberration of the human eye. The results are in agreement with related work and simulations with in-vivo data are according with the produced by a commercial wave-front device. This work is an effort in using to advantage the information acquired for the modern equipment of ophthalmology, besides assisting the understanding of biological visual systems, it also helps the development of artificial vision systems and the designing of optical systems

This thesis aims to solve the mathematical inverse problem of characterizing sea waves based on the responses obtained from a marine vessel sailing under certain sea conditions. By researching this problem the thesis contributes to the marine industry by improving products that are using ocean behavior for controlling ship's dynamics. Knowledge about the current state of the sea, such as the wave frequency and height, is important for navigation, control, and for the safety of a vessel. This information can be retrieved from specialized weather reports. However, such information is not at all time possible to obtain during a voyage, and if so usually comes with a certain delay. Therefore this thesis seeks solutions that can estimate on-line the waves' state using methods in the field of Artificial Intelligence. The specific investigation methods are Transfer Functions augmented with Genetic Algorithm, Artificial Neural Networks and Case-Based Reasoning. These methods have been configured and validated using the n-fold cross validation method. All the methods have been tested with an actual implementation. The algorithms have been trained with data acquired from a marine simulation program developed in Simulink. The methods have also been trained and tested using monitored data acquired from an actual ship sailing on the Baltic Sea as well as wave data obtained from a buoy located nearby the vessel's route. The proposed methods have been compared with state-of-the art reports in order evaluate the novelty of the research and its potential applications in industry. The results in this thesis show that the proposed methods can in fact be used for solving the inverse problem. It was also found that among the investigated methods it is the Transfer Function augmented with Genetic Algorithm which yields best results. This Master Thesis is conducted under the Master of Engineering Program in Robotics at Mälardalens högskola in Västerås, Sweden. The thesis was proposed by Q-TAGG R&D AB in Västerås, Sweden, a company which specializes in marine vessel dynamics research.