Οι υπνικές άτρακτοι είναι απότομες αλλαγές της ρυθμικής δραστηριότητας που χαρακτηρίζονται από σταδιακή αύξηση και κατόπιν μείωση του πλάτους. Εμφανίζονται κυρίως στα στάδια 2,3 και 4 του υπνικού εγκεφαλογράμματος. Τοπογραφικές αναλύσεις έχουν δείξει την ύπαρξη δύο ξεχωριστών τύπων υπνικών ατράκτων, «αργές» και «ταχείς», περίπου στα 12 και 14 Hz, αντίστοιχα. Υπάρχουν ενδείξεις ότι υπάρχουν τουλάχιστον δύο, λειτουργικά, ξεχωριστές γεννήτριες υπνικών ατράκτων, που αντιστοιχούν στις κλάσεις συχνοτήτων. Ο λόγος της εργασίας αυτής ήταν η επεξεργασία υπνικών ατράκτων με την τεχνική Ανάλυσης Ανεξάρτητων Συνιστωσών (ICA) με σκοπό την έρευνα της πιθανότητας εξαγωγής, στα από την ICA ανακατασκευαζόμενα ηλεκτροεγκεφαλογραφήματα (ΗΕΓ), «συνιστωσών» ατράκτων που αντιστοιχούν σε ξεχωριστές δομές ΗΕΓ, και η μελέτη των πηγών που δημιουργούν αυτές τις συνιστώσες. Χρησιμοποιήθηκαν 8κάναλες καταγραφές υπνικών ατράκτων ΗΕΓ από έναν εξεταζόμενο, που καταγράφηκαν στα πλαίσια του Biopattern Network of Excellence, οι οποίες αρχικά επεξεργάστηκαν με ένα φίλτρο FIR με συχνότητες αποκοπής (-3dB) στα 6 και 21 Hz. Κατόπιν εφαρμόστηκε η ανάλυση ICA και εξάχθηκαν οι ανεξάρτητες συνιστώσες (ICs). Έγινε επιλογή των συνιστωσών οι οποίες θα ανακατασκεύαζαν τα ΗΕΓ και τέλος ανακατασκευάσθηκαν αυτά. Στα ανακατασκευασμένα ΗΕΓ έφαρμόστηκε η ανάλυση LORETA. Πρωτού γίνει όμως αυτό έγινε μία εξομείωση του «ευθύ» και «ανάστροφου» προβλήματος. Αυτό έγινε για να μελετήσουμε κατά πόσον θα μπορούσαμε να εξάγουμε αξιόπιστα αποτελέσματα από την τεχνική LORETA με τόσο μικρό αριθμό καναλιών καταγραφής. Η μελέτη αυτή έδειξε ότι τα αποτελέσματά μας θα μπορούσαν να μας δώσουν αξιόπιστες πληροφορίες όσον αφορά την ευρεία περιοχή παραγωγής των ατράκτων και όχι την ακριβή τους θέση. Τα τελικά αποτελέσματα έδειξαν ότι υπάρχει διαφοροποίηση, όσον αφορά την περιοχή παραγωγής τους, και σταθερότητα των πηγών που σχετίζονται με συνιστώσες ατράκτων που ανακατασκευάζονται από ξεχωριστές ομάδες ανεξαρτήτων συνιστωσών (ICs). / Sleep spindles are bursts of rhythmic activity characterized by progressively increasing, then gradually decreasing amplitude, present predominantly in stages 2, 3 and 4 of the sleep electroencephalogram (EEG). Topographic analyses of sleep spindle incidence suggested the existence of two distinct sleep spindle types, “slow” and “fast” spindles at approximately 12 and 14 Hz respectively. There are indications that there exist at least two functionally separated spindle generators, corresponding to each frequency spectrum class. The purpose of the present study was to process sleep spindles with Independent Component Analysis (ICA) in order to investigate the possibility of extracting, in the ICA-reconstructed EEG, spindle “components” corresponding to separate EEG activity patterns, and to investigate the sources underlying these spindle components. We used 8-channel EEG recordings of sleep spindles of a single subject, recorded in the framework of the Biopattern Network of Excellence, which were processed by a FIR filter with cut-off frequencies (-3 dB) at 6 and 21 Hz. Afterwards, ICA was applied and ICs were extracted. There were a choice of the ICs which would reconstruct the EEG and the EEG were finally reconstructed. Source analysis using Low-Resolution Brain Electromagnetic Tomography (LORETA) was applied on the reconstructed EEGs. Before that we made a simulation of the “direct” and “inverse” problem. This was made in order to investigate if we would extract reliable results from the LORETA technique with only 8-channel recordings. The investigation stated that the results could give reliable information only for the brain sites at which the spindle generators were located and not for their exact position. Results indicate separability and stability of sources related to sleep spindle components reconstructed from separate groups of Independent Components (ICs).

The task of automatically recognizing targets in IR imagery has a history of approximately 25 years of research and development. ATR is an application of pattern recognition and scene analysis in the field of defense industry and it is still one of the challenging problems. This thesis may be viewed as an exploratory study of ATR problem with encouraging recognition algorithms implemented in the area. The examined algorithms are among the solutions to the ATR problem, which are reported to have good performance in the literature. Throughout the study, PCA, subspace LDA, ICA, nearest mean classifier, K nearest neighbors classifier, nearest neighbor classifier, LVQ classifier are implemented and their performances are compared in the aspect of recognition rate. According to the simulation results, the system, which uses the ICA as the feature extractor and LVQ as the classifier, has the best performing results. The good performance of this system is due to the higher order statistics of the data and the success of LVQ in modifying the decision boundaries.

Thesis (M.A.)--State University of New York at Binghamton, Department of Anthropology, 2005. / Includes bibliographical references (leaves 81-91).

Σκοπός της παρούσας διπλωματικής εργασίας είναι η μελέτη του αντίστροφου καθορισμού πηγής (inverse source localization problem) και του ρυθμού μ (mu). Έχοντας ως δεδομένο το σήμα του ΗΕΓ γίνεται προσπάθεια µέσω της εφαρμογής της μεθόδου Ανάλυσης Ανεξάρτητων συνιστωσών (ICA) να προσδιοριστούν οι συνιστώσες οι οποίες σχετίζονται με τις περιοχές του εγκεφάλου που ενεργοποιούνται από την κίνηση των χεριών. Με βάση τη λειτουργία της αισθητηριοκινητικής περιοχής του εγκεφάλου και τις ιδιότητες του ρυθμού μ, γίνεται μια μελέτη πάνω στις συνιστώσες που προκύπτουν από την ICA τόσο σε δεδομένα από πραγματική κίνηση, όσο και σε δεδομένα από νοερή κίνηση, καθώς και στην εφαρμογή που μπορεί να υπάρχει σε συστήματα Διεπαφής Εγκεφάλου – Υπολογιστή. / The subject of this diploma thesis is the study of the inverse source localization problem and the mu rhythm. Performing Independent Component Analysis (ICA) on EEG data, we try to specify the components that are related to the brain areas activated by hand movement. By focusing on the function of the somatosensory brain area and the properties or mu rhythm, we study the components resulting from Independent Component Analysis on data of both real and imaginary movement, as well as the possible implementations on Brain – Computer Interface systems.

Το θέμα της κατασκευής ενός συστήματος αναγνώρισης προτύπων για τα ηχητικά σήματα ενός ανθρώπου που κοιμάται είναι ένα από τα ανοιχτά ζητήματα της Βιοιατρικής. Στην παρούσα διπλωματική εξετάζουμε την εξαγωγή ερμηνεύσιμων σημάτων που αντιστοιχούν στον καρδιακό ρυθμό, την αναπνοή και το ροχαλητό. Χρησιμοποιούμε μεθόδους Ανάλυσης σε Ανεξάρτητες Συνιστώσες και μεθόδους Τυφλού Διαχωρισμού που εκμεταλεύονται Στατιστικές Δεύτερης Τάξης. Συμπεραίνουμε ότι οι δεύτερες είναι οι πλέον κατάλληλες όταν συνοδεύονται από ένα στάδιο προεπεξεργασίας που αφορά ανάλυση σε ζώνες συχνοτήτων. / The design of a non-intrusive Pattern Recognition System to estimate the sleep sounds is an open problem of Bioengineering. We use recordings from body-sensors to estimate the heart beat, the breathing and the snoring. In this thesis we examine the effectiveness of Independent Component Analysis for this Blind Source Separation Problem and we compare it with methods that perform Source Separation using Second Order Statistics. We take into account the temporal structure of the sources as well as the presence of noise. Our system is greatly improved by a preprocessing stage of targeted subband decomposition which uses a priori knowledge about the sources. We propose an efficient solution to this problem which is confirmed by medical data.

Σκοπός της παρούσας διπλωματικής εργασίας είναι η δημιουργία ενός συστήματος μίξης ηχητικών σημάτων και προσπάθεια διαχωρισμού τους με βάση τις μεθόδους τυφλού διαχωρισμού σημάτων. Έχοντας ως δεδομένα τα αρχικά σήματα των πηγών γίνεται προσπάθεια, αρχικά μέσω της εφαρμογής της μεθόδου Ανάλυσης Ανεξάρτητων Συνιστωσών (ICA) για την περίπτωση της στιγμιαίας μίξης και στη συνέχεια μέσω της χρήσης αλγορίθμων που στηρίζονται στο μοντέλο παράλληλου παράγοντα (PARAFAC) για την περίπτωση της συνελικτικής μίξης, να προσδιοριστούν τα σήματα των πηγών από τα σήματα μίξης. Επιπλέον, τροποποιώντας τις παραμέτρους του συστήματος που μελετάμε σε κάθε περίπτωση, προσπαθούμε να πετύχουμε τη βέλτιστη απόδοση του διαχωρισμού. / The subject of this diploma thesis is the creation of a mixing system of speech signals and the attempt of their separation using the methods of blind source separation (BSS). Considering the original source signals known, we attempt, firstly by using independent component analysis for instantaneous mixtures and then by using PARAFAC model for convolutive mixtures, to extract the original source signals from the mixing signals. Moreover, by modifying the parameters of the system we make an effort to achieve the best performance of the separation.

A pesar de que algunos autores lo consideraban la “reyna de las pruebas”, el estudio de la confesión no ha tenido mucha acogida en nuestra doctrina, en otras palabras, su análisis no ha sido objeto de mayor desarrollo en el ámbito académico, no obstante su contribución y riqueza práctica para los propios fines del proceso penal. En nuestro quehacer como magistrada de segundo nivel de una Sala Penal de Lima, hemos tenido la oportunidad de apreciar de cerca cuáles eran las vicisitudes que se presentaban al momento de decidir sobre la valoración probatoria de la confesión sincera, pues cabe la posibilidad de que incida directamente en la disminución de la pena, más aun si consideramos que en la norma no se encuentra desarrollada cuáles son los supuestos a tener en cuenta y se deja mucho a la discreción de los magistrados. Incluso es de considerar que aun la propia Corte Suprema de nuestro país no ha sido uniforme en los criterios adoptados ante los distintos casos en que ha tenido oportunidad de pronunciarse, a pesar que tal decisión repercute directamente en uno de los valores y derechos fundamentales más importantes de la persona humana: su libertad, pues la adopción de una determinada postura influenciará directamente en un mayor o menor tiempo de privación de libertad que pueda sufrir una persona a través de una sentencia condenatoria. Todo esto nos ha llevado a que nuestra investigación se centre en esta figura, y sobre la cual aún persisten inquietudes y divergencias sobre su naturaleza jurídica, es decir: si es un acto procesal, prueba o medio de prueba, tema sobre el cual también estaremos adoptando una postura. A partir del análisis de la pena, del razonamiento judicial, de la teoría del proceso penal y la prueba, ingresaremos a desarrollar el marco teórico que sustenta la confesión, para posteriormente explicar los resultados de nuestra investigación. Esperamos haber cumplido con los objetivos de la cátedra. / Tesis

Made available in DSpace on 2015-03-13T17:08:29Z (GMT). No. of bitstreams: 1 AnaBSC_1-80_DISSERT.pdf: 4024525 bytes, checksum: 9a08adfc78954bdda877bd0993429428 (MD5) Previous issue date: 2010-07-29 / This thesis presents diagenetic and provenance studies of sandstones belonging to the Rift Tectonosequence of the Rio do Peixe and Araripe basins. These basins are located in the interior of Northeast Brazil aligned along the Trend-Cariri Potiguar. Their origin is related to the Early Cretaceous rifting event. In terms of lithostratigraphy, the studied section corresponds to the Antenor Navarro, Sousa and Rio Piranhas formations of the Rio do Peixe Basin, and the Miss?o Velha and Abaiara formations of the Araripe Basin, outcropping in the central-west Cariri Valley. A facies analysis was performed and identified nine distinct sedimentary facies for the Rio de Peixe Basin and ten sedimentary facies for the Araripe Basin, individualized according to the different rock types and their sedimentary structures. These facies associations to led paleoenvironments interpretations and their vertical succession allowed understanding the evolution of the depositional setting during the cronostratigraphic interval studied in these basins. Based on petrographic and diagenetic studies it was possible to characterize the texture and mineralogy of these sandstones, identifying their diagenetic stage and the grain framework provenance. The petrographic study allowed to classify the lithotypes studied in both basins as quartzarenites. Such quartzarenites, in general, are rich in quartz, feldspar and lithic fragment grains, and at accessory levels tourmaline, sphene, zircon, epidote and other mineralogy. The diagenetic history of the studied rocks proved to be very complex, being characterized by a variety mineral of phases that succeeded each other during the eo, meso and telodiagenetic stages. According to the studied formation and the textural and compositional aspects of the rocks, some processes were more or less active, while others were even absent. The eodiagenetic stage is marked by mechanical infiltration of clays and early mechanical compactional processes. The mesodiagenetic phase is characterized by continuity of the mechanical compaction and the beggining of chemical compaction, with quartz and feldspar overgrowths, precipitation of kaolinite, alteration of framework grains to chlorite and illite, and finally, precipitation of opaque minerals. The telodiagenetic stage is represented by the oxidation of some grains, matrix and cements. For the provenance analysis of the studied sandstones were used ternary diagrams whose vertices correspond to the percentage of quartz, feldspar and lithic fragments. This study allowed identifies the source area of these rocks as continental blocks. It was also possible, based on the chemical stability and mineralogical maturity of the rocks, recognize that the Antenor Navarro Formation of the Rio do Peixe Basin, and the upper section of the Miss?o Velha Formation of Araripe Basin have less maturity and stability when compared with the other studied formations / A presente disserta??o apresenta um estudo diagen?tico e de proveni?ncia dos arenitos que integram a Tectonossequ?ncia Rifte nas bacias do Rio do Peixe e do Araripe. Tais bacias comp?em o conjunto das Bacias Interiores do Nordeste brasileiro. As mesmas encontram-se alinhadas segundo o Trend Cariri-Potiguar, estando geneticamente relacionadas ao rifteamento eocret?ceo. Litoestratigraficamente, o intervalo estudado corresponde ?s forma??es Antenor Navarro, Sousa e Rio Piranhas, na Bacia do Rio do Peixe, e ?s forma??es Miss?o Velha e Abaiara, na Bacia do Araripe, estas ?ltimas aflorantes na por??o centro-oeste do Vale do Cariri. Visando subsidiar os estudos de diag?nese e proveni?ncia foi realizada uma an?lise f?ciol?gica que permitiu identificar nove f?cies sedimentares distintas para a Bacia do Rio do Peixe e dez para a Bacia do Araripe, individualizadas consoantes os diferentes tipos litol?gicos e principais estruturas sedimentares presentes. As associa??es destas f?cies possibilitaram tecer interpreta??es acerca dos paleoambientes nos quais as mesmas est?o inseridas, e suas sucess?es verticais permitiram compreender a evolu??o do cen?rio deposicional durante o intervalo cronoestratigr?fico estudado nestas bacias. Com base nas an?lises petrogr?fica e diagen?tica, foi poss?vel caracterizar textural e mineralogicamente os arenitos estudados, identificar as fases diagen?ticas, bem como tecer interpreta??es sobre a proveni?ncia dos gr?os do arcabou?o. O estudo petrogr?fico permitiu classificar os lit?tipos estudados, em ambas as bacias, principalmente como quartzarenitos. Tais quartzarenitos, de maneira geral, apresentam arcabou?o rico em gr?os de quartzo, feldspatos e fragmentos l?ticos e, em menor percentagem, minerais resistatos (turmalina, esfeno, zirc?o, ep?doto). A hist?ria diagen?tica das rochas estudadas mostrou-se bastante complexa, sendo caracterizada por uma grande variedade de fases que se sucederam durante os est?gios de eo, meso e telodiag?nese. De acordo com a forma??o estudada e as particularidades texturais e composicionais intr?nsecas ?s f?cies destas unidades, alguns processos se mostraram mais ou menos atuantes, outros at? mesmo ausentes. De forma geral o est?gio eodiagen?tico ? marcado pela infiltra??o mec?nica de argilas e in?cio dos processos de compacta??o mec?nica; O est?gio mesodiagen?tico ? caracterizado pela continuidade da compacta??o mec?nica e in?cio dos eventos de compacta??o qu?mica, crescimentos secund?rios de quartzo e de feldspatos, gera??o de caulinita autig?nica, altera??o dos gr?os do arcabou?o para clorita e ilita e, por fim, a precipita??o de minerais opacos. O est?gio telodiagen?tico, por sua vez, ? representado pela oxida??o de alguns dos gr?os, matriz e cimentos presentes. A an?lise de proveni?ncia dos arenitos estudados, utilizando-se diagramas tern?rios, cujos v?rtices correspondem aos percentuais de quartzo, feldspatos e fragmentos l?ticos, permitiu identificar que a ?rea-fonte dessas rochas ? representada por blocos continentais. Foi poss?vel tamb?m, reconhecer que os arenitos da Forma??o Antenor Navarro, da Bacia do Rio do Peixe, e a se??o superior da Forma??o Miss?o Velha, da Bacia do Araripe apresentam maior maturidade mineral?gica e estabilidade qu?mica, ao passo que, as demais forma??es cont?m rochas que, comparativamente, apresentam mais maturidade mineral?gica e estabilidade qu?mica. Tais informa??es permitiram associar as forma??es estudadas em cada uma das bacias, a fases espec?ficas de evolu??o do Est?gio Rifte

Submitted by Priscilla Araujo (priscilla@ibict.br) on 2016-06-23T17:19:42Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) JEAN FREDERICK BRITO XAVIER.pdf: 1785438 bytes, checksum: f17977271213d535cec1a6521da9380b (MD5) / Made available in DSpace on 2016-06-23T17:19:42Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) JEAN FREDERICK BRITO XAVIER.pdf: 1785438 bytes, checksum: f17977271213d535cec1a6521da9380b (MD5) Previous issue date: 2014-09-28 / O presente trabalho investiga a aplicação do software livre ICA-AToM em um dos maiores Arquivos brasileiros: o Arquivo da Marinha. Este software foi arquitetado para funcionar na internet e é baseado em normas arquivísticas internacionais, como a Norma Internacional de Registro de Autoridade Arquivística para Entidades Coletivas, Pessoas e Famílias ISAAR (CPF), a Norma Geral Internacional de Descrição Arquivística - ISAD(G) e a Norma Internacional para Descrição de Instituições com Acervo Arquivístico ISDIAH. Apesar de ter sido criado com base em normas indicadas pelo Conselho Internacional de Arquivos – CIA, esse trabalho questiona até que ponto o ICA-AToM atende ao processo de descrição documental do Arquivo da Marinha. Para medir a eficiência deste sofware, no que diz respeito a garantir o acesso da documentação do Arquivo da Marinha, é realizada, nas análises, uma comparação dos metadados utilizados na versão do ICA-AToM instalada no Arquivo da Marinha com os metadados estabelecidos pela Norma Brasileira Arquivística de Descrição – NOBRADE e pelo Modelo de Requisitos para Sistemas Informatizados de Gestão Arquivística de Documentos e-ARQ Brasil. Buscou-se entender cada um dos metadados especificados nestas normas e relacioná-los com as possíveis vantagens de uso dos mesmos. O resultado obtido nestas comparações foi a constatação de um conjunto de metadados e sugestões para que o Arquivo da Marinha possa otimizar o uso deste software e da sua descrição arquivística, que é fundamental na tarefa de garantir o acesso e a preservação do seu acervo. / The present work investigates the aplication of the free software Ica atom in one of the biggest brazilian archives: the Marine Archive. This software was created to work in the internet and based in archivistic international rules, like the international rule of register of archivistic authority to group entities, people and families ISAAR (CPF), the international rule of archivistic description ISAD(G) and the International standard for describing institutions with archival holdings-ISDIAH. Despite of being created based on rules indicated by the international Council of Archives - CIA, this work questions until what point the ICA-AToM answers to the process of documental description of the Marine Archive. To mesure the eficiency of this software, in order to garantee the access to the documents of the Marine Archive, a comparison of the metadatas used in the version of ICA-AToM, situated in the Marine Archive with the metadatas stablished by the brazilian archivistic rule of description (NOBRADE), is done in the analysis and by the “modelo de requisitos para sistemas informatizados de gestão arquivistica de documentos” - e-ARQ Brasil. There was an attempt to understand each one of the metadatas especyfied in these rules and relate them to the possible advantages of their use. The result of these comparisons was the realization of a group of metadatas and sugestions for that Marine Archive can optimize the use of this software and of its archivistic description, which is fundamental in the ensuring task the access and preservation of its collection.

Circadian Rhythms (CR) are driven by a biological clock called as suprachiasmaticnucleus (SCN), located in a brain region called the hypothalamus. These rhythms are very much necessary in maintaining the sleep and wake cycle at appropriate times in a day. As a starting step towards non-invasive investigation of CR, aim is to study changes in the physiological processes of two Regions of Interest (ROI), the hypothalamus and the visual cortex. This was studied using a functional Magnetic Resonance Imaging (fMRI) technique to investigate for any changes or differences in the Blood Oxygen Level Dependent (BOLD)signals extracted from the ROI during a visual stimulation. We acquired and processed fMRI data to extract BOLD signals from ROI and the extracted signals are again further used to study the correlation with the experimental ON-OFF design paradigm. The extracted BOLD signals varied a lot between the two specified brain regions within the same subject and between three types of fMRI data. These variations were found in terms of number of activated voxels and also Signal to Noise ratio(SNR) level present in the signals. The number of activated voxels and SNR werehigh in visual cortex whereas low number of activated voxels and low SNR were found in hypothalamus. The correlation between BOLD responses from primaryvisual cortex were shown as positive with the experimental stimulation whereas BOLD responses extracted from hypothalamus have shown a negative correlation in time with the experimental stimulation. As a start up of the project, these BOLD responses can provide references for a future use in research studies, especially to further study about change in phase of the BOLD signal extracted exactly from the SCN. These phase responses can then be used to study physiological processing in subjects affected by sleep disorders.