Now showing items 91-110 of 345

    Data and methods for a visual understanding of sign languages 

    Cardoso Duarte, Amanda (Date of defense: 2022-06-27)

    Signed languages are complete and natural languages used as the first or preferred mode of communication by millions of people worldwide. However, they, unfortunately, continue to be marginalized languages. Designing, ...

    Data-driven information-theoretic tools under a second-order statistics perspective 

    Cabrera Estanyol, Ferran de (Date of defense: 2023-07-03)

    (English) A great deal is known about second-order statistics. For many years, most of the signal processing problems have been addressed under the perspective of the first and second-order moments of the data, known to ...

    Deep learning for i-vector speaker and language recognition 

    Ghahabi Esfahani, Omid (Date of defense: 2018-05-29)

    Over the last few years, i-vectors have been the state-of-the-art technique in speaker and language recognition. Recent advances in Deep Learning (DL) technology have improved the quality of i-vectors but the DL techniques ...

    Deriving vertical total electron content maps from SMOS full polarimetric data to compensate the Faraday rotation effect 

    Rubino, Roselena (Date of defense: 2022-09-16)

    The Faraday rotation is a geophysical effect that causes a rotation of the electromagnetic field components emitted by the Earth when it propagates through the ionosphere. It depends on the vertical total electron content ...

    Design and analysis of medium access control protocols for ad hoc and cooperative wireless networks 

    Alonso Zárate, Jesús (Date of defense: 2009-02-25)

    La presente tesis doctoral contribuye a la incesante evolución de las comunicaciones inalámbricas. Se centra en el diseño de protocolos de acceso al medio (MAC) para redes ad hoc y redes inalámbricas cooperativas. En una ...

    Design and implementation of an SDR-based multi-frequency ground-based SAR system 

    Amézaga, Adrià (Date of defense: 2020-11-25)

    Synthetic Aperture Radar (SAR) has proven a valuable tool in the monitoring of the Earth, either at a global or local scales. SAR is a coherent radar system able to image extended areas with high resolution, and finds ...

    Design and implementation of low complexity adaptive optical OFDM systems for software-defined transmission in elastic optical networks 

    Nadal Reixats, Laia (Date of defense: 2014-11-21)

    Due to the increasing global IP traffic and the exponential growing demand for broadband services, optical networks are experimenting significant changes. Advanced modulation formats are being implemented at the Digital ...

    Design and optimization of metro-access networks supporting 5G services 

    Sarmiento Hernández, Samael (Date of defense: 2020-03-26)

    The Internet data traffic constant growth caused by the popularization of cloud services, mobile and social networks, demand changes to the networks in order to enable scalable growth in traffic volume, while supporting a ...

    Design and performance analysis of advanced GNSS-R instruments back-end 

    Pascual Biosca, Daniel (Date of defense: 2020-12-21)

    GNSS reflectometry (GNSS-R) is a set of techniques that uses the reflected GNSS signals over the Earth’s surface as opportunity signals for remote sensing applications. In 1993, the European Space Agency (ESA) suggested ...

    Design and performance evaluation of millimeter-wave flat lens antennas for communications, radar and imaging applications 

    Imbert Villà, Marc (Date of defense: 2016-07-29)

    Millimeter-wave systems introduce a set of particular severe requirements from the antenna point of view in order to achieve specific performances. In this sense, high directive antennas are required to overcome the huge ...

    Design and stochastic analysis of emerging large-scale wireless-powered sensor networks 

    Mekikis, Prodromos-Vasileios (Date of defense: 2017-11-13)

    Undeniably, the progress in wireless networks during the last two decades is extraordinary. However, the ever-increasing upward trend in the numbers of wireless devices that will overwhelm every field of our everyday life, ...

    Design of efficient microwave power amplifier systems 

    Niotaki, Kyriaki (Date of defense: 2014-12-15)

    In the future communication systems, it is of key importance that the transceivers are capable of operating in multiple frequency bands and with complex signals. In this context, the power amplifier is a critical component ...

    Design of energy efficient network planning schemes for LTE-based cellular networks 

    Bousia, Alexandra (Date of defense: 2016-02-18)

    The rapid expansion of mobile services and the emerging demand for multimedia applications have led to an impressive traffic growth. To this end, Mobile Network Operators (MNOs) seek to extend their infrastructure by ...

    Design of isofrequency reconfigurable repeaters 

    Díaz Tapia, Edgar (Date of defense: 2013-10-28)

    The advances in the communications systems has brought new requirements and challenges in terms of compactness and efficient systems that looking for increase the signal coverage area. The reconfigurable antennas are a ...

    Design rules and optimization of electro-optic modulators based on coplanar waveguides 

    Ibarra Fusté, José Antonio (Date of defense: 2014-02-03)

    Electro-optical traveling wave modulators (EO-TWM) are basic building blocks of the optical communications industry which is leading a revolution in the way we communicate, work and live. As a result, the demand for ...

    Detection and handling of overlapping speech for speaker diarization 

    Zelenák, Martin (Date of defense: 2012-01-31)

    For the last several years, speaker diarization has been attracting substantial research attention as one of the spoken language technologies applied for the improvement, or enrichment, of recording transcriptions. ...

    Development of novel instruments and techniques for passive microwave remote sensing 

    Muñoz Martin, Joan Francesc (Date of defense: 2021-06-17)

    Earth Observation using satellites has helped to better model our planet. The goal of such systems is to provide large data sets to help to understand the effects of our actions on the climate, to predict storms in near ...

    Digital design and experimental validation of high-performance real-time OFDM systems 

    Font Bach, Josep Oriol (Date of defense: 2013-07-26)

    The goal of this Ph.D. dissertation is to address a number of challenges encountered in the digital baseband design of modern and future wireless communication systems. The fast and continuous evolution of wireless ...

    Discriminative features for GMM and i-vector based speaker diarization 

    Zewoudie, Abraham Woubie (Date of defense: 2017-09-20)

    Speaker diarization has received several research attentions over the last decade. Among the different domains of speaker diarization, diarization in meeting domain is the most challenging one. It usually contains spontaneous ...

    Diseño de amplificadores de bajo ruido en banda milimétrica 

    Pradell, Lluís (Date of defense: 1989-11-16)

    Sin tener en cuenta introducción y conclusiones, la tesis doctoral esta dividida en 6 capítulos. Los dos primeros tratan del ruido eléctrico asociado a los dispositivos activos (transistores Gaas Fet y Hemt) utilizados en ...