Atenuação de ruídos coerentes utilizando decomposição em modos empíricos

The seismic processing technique has the main objective to provide adequate picture of geological structures from subsurface of sedimentary basins. Among the key steps of this process is the enhancement of seismic reflections by filtering unwanted signals, called seismic noise, the improvement of signals of interest and the application of imaging procedures. The seismic noise may appear random or coherent. This dissertation will present a technique to attenuate coherent noise, such as ground roll and multiple reflections, based on Empirical Mode Decomposition method. This method will be applied to decompose the seismic trace into Intrinsic Mode Functions. These functions have the properties of being symmetric, with local mean equals zero and the same number of zero-crossing and extremes. The developed technique was tested on synthetic and real data, and the results were considered encouraging

Retratos da dignidade: negros do riacho: identidade educação fotografia (2005-2007)

Portraits de la Dignité: Noirs du Riacho (2005-2006) analyse le Projet Dignité, comme un produit publicitaire du gouverne du Rio Grande do Norte, à travers de trois voie: l éducation; l identité; la propagande publicitaire. Notre regard a été dirigé vers les images écrites, parlés et photografiées pour meilleur comprendre comme la communauté des Noirs du Riacho, a été incorporer a polítique d égalité de races proposé par les gouvernes Municipal, de l État, et Fédéral, tout em transformant la communauté en produit publicitaire du gouverne. Entre une partie et l outre on a enregistrés des questions sur l identité, plus particulierment la (des)constrution identitaire tout en s appuyant dans le rôle de la langage publicitaire, que em utilisand les richeses de ses techniques, montre le Riacho et le peuple dans la exposition etno-photogaphique Portraits de la Dignité. Ainsi, c est important comprendre la divulgation du Projet Dignité, appuyer dans la propragande de l image des personnages du Riacho divulguées dans la presse locale. Cette problematique, nos conduit a controverser des questions três anciennes par rapports aux discriminations contre les négres, ainsi comme la façon que le gouvernement en la période analysé, s engage en la problematique des communautés restantes de quilombolas dans l État du Rio Grande do Norte. Au choisir la communauté du Riacho pour développer sa politique d action affirmative l État place le Riacho comme laboratoire sociale , en cette contexte nous cherchons à travers des analyses des documents officiels, thèses, recherches bibliografiques et de champs, bien comme de matériel journalistique et publicitaire, révéler les messages véhiculés dans la presse locale sur des questions proposés par cette étude. Pour développer l étude nous appuyons metodologicament en la recherche qualitative, sans perdre de vue l analyse critique des contenus, vu que les sujets en étude ne doive pas être analyser basé en un unique point de vue. Ainsi, nous pensons ne pas fermer la question, mas ouvrir l outres pour permettre meilleur débattre la liason chaque jour plus fort entre la publicité e l action gouvernamentale, en ce qui est relatif aux usages de l image photografique

Atenuação de ruídos coerentes utilizando decomposição em modos empíricos

The seismic processing technique has the main objective to provide adequate picture of geological structures from subsurface of sedimentary basins. Among the key steps of this process is the enhancement of seismic reflections by filtering unwanted signals, called seismic noise, the improvement of signals of interest and the application of imaging procedures. The seismic noise may appear random or coherent. This dissertation will present a technique to attenuate coherent noise, such as ground roll and multiple reflections, based on Empirical Mode Decomposition method. This method will be applied to decompose the seismic trace into Intrinsic Mode Functions. These functions have the properties of being symmetric, with local mean equals zero and the same number of zero-crossing and extremes. The developed technique was tested on synthetic and real data, and the results were considered encouraging

Mídia e produção de sentido: a reconfiguração da indústria da música e as estratégias discursivas da associação cultural DoSol

This dissertation aims to analyse discursive strategies from Dosol in order to understand the present elements to keep its audience and the marketing activities. Based on French line of discourse analysis We look into the articles posted on its website at http://www.dosol.com.br within 2010 and We foment dialogues among music, media and communications researchers. Participant observation is slightly used on the critical perception and views of researched object to confront situations and step up, with theorists, the major part of closing remarks. The obtained results indicate a website speech paved on afirmative policies and social capital, trying to keep/seduce its audience with the efect of the intended credibility meaning. The economic factor wanders the speech so often that the speaker assumes a entrepreneur/cultural producer. As a niche market, Dosol assumes a main role in music industry for releasing the regional and local cultural production. On the other hand, it is noticeable that its sustainability and media visibility, as it is seen today, depends on the laws tor promote Culture, what denotes a lack of a regional cultural policies to medium and long term at Rio Grande do Norte

Caracterização de células de lugar no hipocampo e de suas relações com oscilações do potencial de campo local

The main inputs to the hippocampus arise from the entorhinal cortex (EC) and form a loop involving the dentate gyrus, CA3 and CA1 hippocampal subfields and then back to EC. Since the discovery that the hippocampus is involved in memory formation in the 50's, this region and its circuitry have been extensively studied. Beyond memory, the hippocampus has also been found to play an important role in spatial navigation. In rats and mice, place cells show a close relation between firing rate and the animal position in a restricted area of the environment, the so-called place field. The firing of place cells peaks at the center of the place field and decreases when the animal moves away from it, suggesting the existence of a rate code for space. Nevertheless, many have described the emergence of hippocampal network oscillations of multiple frequencies depending on behavioral state, which are believed to be important for temporal coding. In particular, theta oscillations (5-12 Hz) exhibit a spatio-temporal relation with place cells known as phase precession, in which place cells consistently change the theta phase of spiking as the animal traverses the place field. Moreover, current theories state that CA1, the main output stream of the hippocampus, would interplay inputs from EC and CA3 through network oscillations of different frequencies, namely high gamma (60-100 Hz; HG) and low gamma (30-50 Hz; LG), respectively, which tend to be nested in different phases of the theta cycle. In the present dissertation we use a freely available online dataset to make extensive computational analyses aimed at reproducing classical and recent results about the activity of place cells in the hippocampus of freely moving rats. In particular, we revisit the debate of whether phase precession is due to changes in firing frequency or space alone, and conclude that the phenomenon cannot be explained by either factor independently but by their joint influence. We also perform novel analyses investigating further characteristics of place cells in relation to network oscillations. We show that the strength of theta modulation of spikes only marginally affects the spatial information content of place cells, while the mean spiking theta phase has no influence on spatial information. Further analyses reveal that place cells are also modulated by theta when they fire outside the place field. Moreover, we find that the firing of place cells within the theta cycle is modulated by HG and LG amplitude in both CA1 and EC, matching cross-frequency coupling results found at the local field potential level. Additionally, the phase-amplitude coupling in CA1 associated with spikes inside the place field is characterized by amplitude modulation in the 40-80 Hz range. We conclude that place cell firing is embedded in large network states reflected in local field potential oscillations and suggest that their activity might be seen as a dynamic state rather than a fixed property of the cell.