264 research outputs found

    Erodibilidad de los inceptisoles del término municipal de Badajoz. España

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    Se ha estudiado la erodibilidad de los inceptisoles del término municipal de Badajoz mediante la aplicación de una ecuación de regresión desarrollada por el ICONA, observándose una gran variabilidad entre los distintos suelos estudiados a pesar de pertenecer todos ellos al mismo subgrupo, xerochrept. Esta variabilidad nos viene marcada, fundamentalmente, por la textura de dichos suelos, parámetro que nos indica, en definitiva el riesgo innato de los suelos a ser erosionados.The erodibility of the inceptisols of the township of Badajoz has been studied by means of the application of a regresion equation developed by the ICONA, being observed a great variability among the different soils studied in spite belonging all of them to the same subgroup, xerochrept. This variability is marked, fundamentally, because of the texture of this soils, a parameter that indicates us, in definitive, the innate risk of the soils to be eroded

    Accessibility dynamics and regional cross-border cooperation (CBC) perspectives in the portuguese—spanish borderland

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    Accessibility plays a major role in achieving sustainable transport, and therefore urban and regional sustainability. The urban public transport system promotes mobility and realizes a large part of urban movements. Moreover, improving accessibility in order to promote sustainable transport requires the application of new concepts and indicators as a powerful tool in the process of creating a balanced urban transport system. In this regard, one of the main goals of this research is to present an overview of the relevant accessibility indicators and assessment of accessibility in regional Cross-Border Cooperation (CBC) in order to transcendence challenges and obstacles for sustainable transportation in these regions along of Portuguese-Spanish border. This paper focuses on the accessibility of cross-border cooperation scenarios along the border regions of Alto Alentejo (Portugal) and Badajoz (Spain) where the Case Study Research Method (CSR) made it possible to recognize accessibility as a key factor in territorial success. Also, accessibility analysis can assess improvements as well as regional imbalances. In addition, this methodology can be used to identify missing links, which requires new investments enabling long-term sustainability.info:eu-repo/semantics/publishedVersio

    Improving automatic detection of obstructive sleep apnea through nonlinear analysis of sustained speech

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    We present a novel approach for the detection of severe obstructive sleep apnea (OSA) based on patients' voices introducing nonlinear measures to describe sustained speech dynamics. Nonlinear features were combined with state-of-the-art speech recognition systems using statistical modeling techniques (Gaussian mixture models, GMMs) over cepstral parameterization (MFCC) for both continuous and sustained speech. Tests were performed on a database including speech records from both severe OSA and control speakers. A 10 % relative reduction in classification error was obtained for sustained speech when combining MFCC-GMM and nonlinear features, and 33 % when fusing nonlinear features with both sustained and continuous MFCC-GMM. Accuracy reached 88.5 % allowing the system to be used in OSA early detection. Tests showed that nonlinear features and MFCCs are lightly correlated on sustained speech, but uncorrelated on continuous speech. Results also suggest the existence of nonlinear effects in OSA patients' voices, which should be found in continuous speech

    Exploring differences between phonetic classes in Sleep Apnoea Syndrome Patients using automatic speech processing techniques

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    This work is part of an on-going collaborative project between the medical and signal processing communities to promote new research efforts on automatic OSA (Obstructive Apnea Syndrome) diagnosis. In this paper, we explore the differences noted in phonetic classes (interphoneme) across groups (control/apnoea) and analyze their utility for OSA detectio

    Severe apnoea detection using speaker recognition techniques

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    Proceedings of the International Conference on Bio-inspired Systems and Signal Processing (BIOSIGNALS 2009)The aim of this paper is to study new possibilities of using Automatic Speaker Recognition techniques (ASR) for detection of patients with severe obstructive sleep apnoea (OSA). Early detection of severe apnoea cases can be very useful to give priority to their early treatment optimizing the expensive and timeconsuming tests of current diagnosis methods based on full overnight sleep in a hospital. This work is part of an on-going collaborative project between medical and signal processing communities to promote new research efforts on automatic OSA diagnosis through speech processing technologies applied on a carefully designed speech database of healthy subjects and apnoea patients. So far, in this contribution we present and discuss several approaches of applying generative Gaussian Mixture Models (GMMs), generally used in ASR systems, to model specific acoustic properties of continuous speech signals in different linguistic contexts reflecting discriminative physiological characteristics found in OSA patients. Finally, experimental results on the discriminative power of speaker recognition techniques adapted to severe apnoea detection are presented. These results obtain a correct classification rate of 81.25%, representing a promising result underlining the interest of this research framework and opening further perspectives for improvement using more specific speech recognition technologiesThe activities described in this paper were funded by the Spanish Ministry of Science and Technology as part of the TEC2006-13170-C02-01 project

    Assessing Land-Use Changes in European Territories: A Retrospective Study from 1990 to 2012

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    The need to understand what land use is has motivated the development of programmes that aims to identify it and quantify it—CORINE Land Cover (CLC) in 1985. From this official and open geodatabase—through the using of geographic information system (GIS) tools—the amount of area established for each land use has been identified in all the 28 member states of the EU. This mostly corresponds to agricultural and forestry uses. Between 1990 and 2012, it was possible to determine countries with variable land use models such as Finland, Latvia, Portugal and Spain—the rest of the states presenting stable land use models. Additionally, some countries are characterized by the predominance of one or two land uses. Contextually, the proposal aims to develop a retrospective study regarding the land-use changes in the EU territories from 1990 to 2012, through the available tools such as CLC

    Assessment of severe apnoea through voice analysis, automatic speech, and speaker recognition techniques

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    The electronic version of this article is the complete one and can be found online at: http://asp.eurasipjournals.com/content/2009/1/982531This study is part of an ongoing collaborative effort between the medical and the signal processing communities to promote research on applying standard Automatic Speech Recognition (ASR) techniques for the automatic diagnosis of patients with severe obstructive sleep apnoea (OSA). Early detection of severe apnoea cases is important so that patients can receive early treatment. Effective ASR-based detection could dramatically cut medical testing time. Working with a carefully designed speech database of healthy and apnoea subjects, we describe an acoustic search for distinctive apnoea voice characteristics. We also study abnormal nasalization in OSA patients by modelling vowels in nasal and nonnasal phonetic contexts using Gaussian Mixture Model (GMM) pattern recognition on speech spectra. Finally, we present experimental findings regarding the discriminative power of GMMs applied to severe apnoea detection. We have achieved an 81% correct classification rate, which is very promising and underpins the interest in this line of inquiry.The activities described in this paper were funded by the Spanish Ministry of Science and Technology as part of the TEC2006-13170-C02-02 Project

    Comparative analysis of ephemeral river ecosystem services in agricultural and natural landscapes in mediterranean environments. A practical approach to Caia River (Portugal)

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    Mediterranean landscapes present a large amount of biodiversity and ecosystems leading to their unique identity. In fact, it is increasingly acknowledged that these ecosystems provide a large range of benefits, not only for the area where they are located but also for their surroundings. Benefits that may vary from aesthetical values to socioeconomic aspects that might influence territorial development, including also the preservation of those ecosystems. The ephemeral and intermittent rivers provide several and pivotal ecosystem services within to the environment. However, these services differ a lot from agricultural to natural landscapes – e.g. agricultural landscapes structure ́ is susceptible to dramatic changes through the seasons and water cycles. Thus, a comparison study between agricultural and natural Mediterranean environments landscapes have been carried out – allowing to deeply understand ephemeral rivers ecosystems systems and their dynamics. Considering the purpose of the study - a comparison analysis between river ecosystem services in agricultural and natural landscapes in Mediterranean environments have been conducted. Therefore, a Cross-Border ephemeral river – Caia River (Portugal-Spain) have been selected as a case study. The comparison has covered cultural, aesthetic, functional and socio-economic ecosystem services; showing the relevance of the functions granted by the river

    Determinação da aptidão biogeofísica do território EUROACE para a utilização agroflorestal

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    É consensual que a escolha dos usos mais adequados às aptidões edafo-climáticas, complementada com critérios socioeconómicos, promove uma utilização sustentável dos espaços rurais. Existem, no entanto, diferentes metodologias utilizadas para a definição da capacidade e potencialidade do solo para a implementação de usos agroflorestais ou manutenção de ecossistemas naturais e seminaturais, nomeadamente culturas agrícolas, povoamentos florestais, territórios agro-silvo-pastoris e áreas prioritárias para a conservação da natureza. Muitas dessas metodologias recorrem a sistemas de apoio à decisão, baseados na análise espacial multicritério. Neste estudo pretendeu-se determinar os diferentes níveis de aptidão para a utilização agroflorestal no território transfronteiriço que abrange o Alentejo, Extremadura e o Centro (Euro-região EUROACE). Para o efeito recorreu-se a um conjunto de variáveis edáficas e topográficas. Foram igualmente incorporadas as condicionantes legais e a ocupação do solo. A avaliação da aptidão foi efetuada com recurso ao método de análise espacial multicritério Analytic Hierarchy Process (AHP). O resultado obtido com esta metodologia, confrontado com a matriz de uso existente, permite identificar as áreas onde a ocupação e gestão está de acordo com a aptidão do espaço, bem como as áreas onde o uso deverá ser alvo de uma reconversão ou apenas a uma alteração de modo de gestão

    Phoneme and Sub-Phoneme T-Normalization for Text-Dependent Speaker Recognition

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    Test normalization (T-Norm) is a score normalization technique that is regularly and successfully applied in the context of text-independent speaker recognition. It is less frequently applied, however, to text-dependent or textprompted speaker recognition, mainly because its improvement in this context is more modest. In this paper we present a novel way to improve the performance of T-Norm for text-dependent systems. It consists in applying score TNormalization at the phoneme or sub-phoneme level instead of at the sentence level. Experiments on the YOHO corpus show that, while using standard sentence-level T-Norm does not improve equal error rate (EER), phoneme and sub-phoneme level T-Norm produce a relative EER reduction of 18.9% and 20.1% respectively on a state-of-the-art HMM based textdependent speaker recognition system. Results are even better for working points with low false acceptance rates
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