Adaptive modeling and high quality spectral estimation for speech enhancement

In this work an adaptive modeling and spectral estimation scheme based on a dual Discrete Kalman Filtering (DKF) is proposed for speech enhancement. Both speech and noise signals are modeled by an autoregressive structure which provides an underlying time frame dependency and improves time-frequency resolution. The model parameters are arranged to obtain a combined state-space model and are also used to calculate instantaneous power spectral density estimates. The speech enhancement is performed by a dual discrete Kalman filter that simultaneously gives estimates for the models and the signals. This approach is particularly useful as a pre-processing module for parametric based speech recognition systems that rely on spectral time dependent models. The system performance has been evaluated by a set of human listeners and by spectral distances. In both cases the use of this pre-processing module has led to improved results.

Spectral and homogenization problems

Dissertation for the Degree of Doctor of Philosophy in Mathematics

Effects of UV radiation exposure on DNA and DNA repair enzymes

Dissertação para obtenção do Grau de Mestre em Biotecnologia

A Case of Post-Radiotherapy Gastritis: Radiation Does Not Explain Everything

Hemorrhagic gastritis is a possible late toxicity outcome after radical radiotherapy but it is nowadays a very rare condition and most likely depends on other clinical factors. We report the case of a 77-year-old woman with a symptomatic solitary extramedullary intra-abdominal plasmacytoma and multiple gastric comorbidities, treated with external beam radiotherapy. Despite the good response to radiotherapy, the patient experienced multiple gastric bleeding a few months later, with the need of multiple treatments for its control. In this paper we will discuss in detail all aspects related to the different causes of hemorrhagic gastritis.

Preparation of gas-filled porous microparticles (GPPs) and microbubbles (MBs) by PGSS method

Dissertation to obtain the Master Degree in Biotechnology

Gas emissions on rice culture and its importance on air quality

Dissertação para obtenção do Grau de Mestre em Engenharia do Ambiente Perfil Gestão de Sistemas Ambientais

Galp Energia: Oil & Gas: Equity Investment Report

A Work Project, presented as part of the requirements for the Award of a Masters Degree in Finance from the NOVA – School of Business and Economics

Galp Energia: Oil & Gas: Equity Investment Report

A Work Project, presented as part of the requirements for the Award of a Masters Degree in Finance from the NOVA – School of Business and Economics

Spectral and coherence estimates on electroencephalogram recordings during arithmetical tasks

Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para obtenção do Grau de Mestre em Engenharia Biomédica

Gas adsorption in the MIL-53(AI) metal organic framework. Experiments and molecular simulation

Dissertação para obtenção do Grau de Doutor em Engenharia Química

Aplicação clínica - avaliação da técnica acoustic radiation force impulse

Dissertação para obtenção do Grau de Mestre em Engenharia Biomédica

Gas Natural Fenosa: Equity research

A Work Project, presented as part of the requirements for the Award of a Masters Degree in Finance from the NOVA – School of Business and Economics

Adsorption equilibria of flue gas components on activated carbon

Dissertação para obtenção do Grau de Mestre em Engenharia Química e Bioquímica