Made available in DSpace on 2010-04-20T20:14:33Z (GMT). No. of bitstreams: 1 61070100599.pdf: 913078 bytes, checksum: 2e1dc4c65b55c3145bbab188f3146ef0 (MD5) Previous issue date: 2009-03-20T00:00:00Z / Algumas abordagens recentes chamaram a atenção para a importância das empresas mobilizarem sua capacidade produtiva para solucionar problemas das classes menos favorecidas da sociedade. Especificamente para o caso de serviços financeiros, defende-se que a atuação na baixa renda tem implicações positivas na sociedade como um todo, ao promover sua re-inclusão no sistema tradicional. Dentro desse cenário, as iniciativas de microfinanças parecem jogar luz a esse problema ao tentar levar acesso a serviços financeiros para a população de baixa renda. Porém, tais iniciativas ainda parecem não ter demonstrado o seu real potencial, e prova disso é a persistência dos crônicos indicadores de pobreza e de desigualdade social. Isso acontece porque as abordagens atuais de microfinanças apresentam limitações, dentre as quais as tecnológicas são uma das mais importantes. Por outro lado, existe um fenômeno que se manifesta especificamente no Brasil e que se refere ao grande crescimento dos chamados correspondentes bancários (CBs), em que o correspondente, que, na maior parte das vezes, é um varejo, oferta serviços em nome do banco. Alguns estudos relacionam esses dois conceitos, microfinanças e CBs, e propõem o CB como um canal tecnológico para a promoção das microfinanças. Dentro desse cenário, uma pergunta pertinente e ainda pouco explorada na literatura é: como ocorrem a adoção, implementação e uso das tecnologias de correspondentes bancários na oferta de serviços financeiros para a população de baixa renda no Brasil? De posse dessa pergunta de pesquisa, procedeu-se a um estudo de caso em profundidade e o objeto de estudo foi a forma de atuação do Banco Lemon, em especial, por possuir uma extensa rede de CBs, ser baseado exclusivamente em CBs (não tem agências físicas) e estar focado na baixa renda. A partir de uma abordagem que inclui contribuições das escolas do estruturacionismo, do construtuvismo e do contextualismo, foi possível entender como ocorreu o processo de negociação entre dois grupos relevantes, o Banco Lemon e o gestor de redes, que é um intermediário entre o banco e o varejo, na formação da tecnologia que foi adotada, implementada e usada. Os principais achados da pesquisa referem-se ao entendimento de como a tecnologia é usada para prover os serviços que o Banco Lemon quer ofertar e como dois grupos relevantes interagem, negociam e produzem a tecnologia na prática. / Recent approaches highlighted the importance of companies to redirect their productive capacity in order to meet the needs of lower-income people. When it touches financial services, some advocate participating in the lower-income segment has positive impacts on the whole society, since it brings them back to the formal market. In this context, since microfinance initiatives try to deliver financial services to the poor, they seem to throw light on this issue. On the other hand, these initiatives have not yet shown their full potential– persistent chronic poverty and inequity indicators are still at high rates. This may happen because the current microfinance initiatives have limitations, and the technological aspects are among the most important ones. At the same time, another phenomenon that takes place in Brazil is the great growth of the so-called correspondent banking (CB), where the correspondent, most of it retail shops, offer services on behalf of the bank. Some recent studies relate these two concepts–microfinance and CB–, and propose the CB as a technological channel to foster microfinance. In this regard, there is a pertinent but still scarcely developed question in the literature: how do adoption, implementation and use of the correspondent banking technology take place in the supply of financial services to the lowerincome population in Brazil? Taking this research question into account, a deep case study was conducted and its object was Banco Lemon’s way of running businesses, mainly, because it possesses a large CB network, it is based exclusively on CBs–no branches–and it is focused on the lower-income population. Using an approach that included contributions from the body of knowledge of structuralism, constructivism and contextualism, it was possible to understand how was the negotiation held between two relevant groups–Banco Lemon itself and the network integrators, which are intermediaries between Banco Lemon and the retail–in the formation of the adopted, implemented and used technology. Main findings of this research refer to the understanding of how technology is used to provide the services Banco Lemon wants to deliver and how two different relevant groups interact, negotiate and produce the technology in the practice.

[EN] Next-generation terrestrial broadcasting targets at enhancing spectral efficiency to overcome the challenges derived from the spectrum shortage as a result of the progressive allocation of frequencies - the so-called Digital Dividend - to satisfy the growing demands for wireless broadband capacity. Advances in both transmission standards and video coding are paramount to enable the progressive roll-out of high video quality services such as HDTV (High Definition Televison) or Ultra HDTV. The transition to the second generation European terrestrial standard DVB-T2 and the introduction of MPEG-4/AVC video coding already enables the transmission of 4-5 HDTV services per RF (Radio Frequency) channel. However, the impossibility to allocate higher bit-rate within the remaining spectrum could jeopardize the evolution of the DTT platforms in favour of other high-capacity systems such as the satellite or cable distribution platforms. Next steps are focused on the deployment of the recently released High Efficiency Video Coding (HEVC) standard, which provides more than 50% coding gain with respect to AVC, with the next-generation terrestrial standards. This could ensure the competitiveness of the DTT. This dissertation addresses the use of multi-RF channel aggregation technologies to increase the spectral efficiency of future DTT networks. The core of the Thesis are two technologies: Time Frequency Slicing (TFS) and Channel Bonding (CB). TFS and CB consist in the transmission of the data of a TV service across multiple RF channels instead of using a single channel. CB spreads data of a service over multiple classical RF channels (RF-Mux). TFS spreads the data by time-slicing (slot-by-slot) across multiple RF channels which are sequentially recovered at the receiver by frequency hopping. Transmissions using these features can benefit from capacity and coverage gains. The first one comes from a more efficient statistical multiplexing (StatMux) for Variable Bit Rate (VBR) services due to a StatMux pool over a higher number of services. Furthermore, CB allows increasing service data rate with the number of bonded RF channels and also advantages when combined with SVC (Scalable Video Coding). The coverage gain comes from the increased RF performance due to the reception of the data of a service from different RF channels rather that a single one that could be, eventually, degraded. Robustness against interferences is also improved since the received signal does not depend on a unique potentially interfered RF channel. TFS was firstly introduced as an informative annex in DVB-T2 (not normative) and adopted in DVB-NGH (Next Generation Handheld). TFS and CB are proposed for inclusion in ATSC 3.0. However, they have never been implemented. The investigations carried out in this dissertation employ an information-theoretical approach to obtain their upper bounds, physical layer simulations to evaluate the performance in real systems and the analysis of field measurements that approach realistic conditions of the network deployments. The analysis report coverage gains about 4-5 dB with 4 RF channels and high capacity gains already with 2 RF channels. This dissertation also focuses on implementation aspects. Channel bonding receivers require one tuner per bonded RF channel. The implementation of TFS with a single tuner demands the fulfilment of several timing requirements. However, the use of just two tuners would still allow for a good performance with a cost-effective implementation by the reuse of existing chipsets or the sharing of existing architectures with dual tuner operation such as MIMO (Multiple Input Multiple Output). / [ES] La televisión digital terrestre (TDT) de última generación está orientada a una necesaria mejora de la eficiencia espectral con el fin de abordar los desafíos derivados de la escasez de espectro como resultado de la progresiva asignación de frecuencias - el llamado Dividendo Digital - para satisfacer la creciente demanda de capacidad para la banda ancha inalámbrica. Los avances tanto en los estándares de transmisión como de codificación de vídeo son de suma importancia para la progresiva puesta en marcha de servicios de alta calidad como la televisión de Ultra AD (Alta Definición). La transición al estándar europeo de segunda generación DVB-T2 y la introducción de la codificación de vídeo MPEG-4 / AVC ya permite la transmisión de 4-5 servicios de televisión de AD por canal RF (Radiofrecuencia). Sin embargo, la imposibilidad de asignar una mayor tasa de bit sobre el espectro restante podría poner en peligro la evolución de las plataformas de TDT en favor de otros sistemas de alta capacidad tales como el satélite o las distribuidoras de cable. El siguiente paso se centra en el despliegue del reciente estándar HEVC (High Efficiency Video Coding), que ofrece un 50% de ganancia de codificación con respecto a AVC, junto con los estándares terrestres de próxima generación, lo que podría garantizar la competitividad de la TDT en un futuro cercano. Esta tesis aborda el uso de tecnologías de agregación de canales RF que permitan incrementar la eficiencia espectral de las futuras redes. La tesis se centra en torno a dos tecnologías: Time Frequency Slicing (TFS) y Channel Bonding (CB). TFS y CB consisten en la transmisión de los datos de un servicio de televisión a través de múltiples canales RF en lugar de utilizar un solo canal. CB difunde los datos de un servicio a través de varios canales RF convencionales formando un RF-Mux. TFS difunde los datos a través de ranuras temporales en diferentes canales RF. Los datos son recuperados de forma secuencial en el receptor mediante saltos en frecuencia. La implementación de estas técnicas permite obtener ganancias en capacidad y cobertura. La primera de ellas proviene de una multiplexación estadística (StatMux) de servicios de tasa variable (VBR) más eficiente. Además, CB permite aumentar la tasa de pico de un servicio de forma proporcional al número de canales así como ventajas al combinarla con codificación de vídeo escalable. La ganancia en cobertura proviene de un mejor rendimiento RF debido a la recepción de los datos de un servicio desde diferentes canales en lugar uno sólo que podría estar degradado. Del mismo modo, es posible obtener una mayor robustez frente a interferencias ya que la recepción o no de un servicio no depende de si el canal que lo alberga está o no interferido. TFS fue introducido en primer lugar como un anexo informativo en DVB-T2 (no normativo) y posteriormente fue adoptado en DVB-NGH (Next Generation Handheld). TFS y CB han sido propuestos para su inclusión en ATSC 3.0. Aún así, nunca han sido implementados. Las investigaciones llevadas a cabo en esta Tesis emplean diversos enfoques basados en teoría de la información para obtener los límites de ganancia, en simulaciones de capa física para evaluar el rendimiento en sistemas reales y en el análisis de medidas de campo. Estos estudios reportan ganancias en cobertura en torno a 4-5 dB con 4 canales e importantes ganancias en capacidad aún con sólo 2 canales RF. Esta tesis también se centra en los aspectos de implementación. Los receptores para CB requieren un sintonizador por canal RF agregado. La implementación de TFS con un solo sintonizador exige el cumplimiento de varios requisito temporales. Sin embargo, el uso de dos sintonizadores permitiría un buen rendimiento con una implementación más rentable con la reutilización de los actuales chips o su introducción junto con las arquitecturas existentes que operan con un doble sintonizador tales como / [CAT] La televisió digital terrestre (TDT) d'última generació està orientada a una necessària millora de l'eficiència espectral a fi d'abordar els desafiaments derivats de l'escassetat d'espectre com a resultat de la progressiva assignació de freqüències - l'anomenat Dividend Digital - per a satisfer la creixent demanda de capacitat per a la banda ampla sense fil. Els avanços tant en els estàndards de transmissió com de codificació de vídeo són de la màxima importància per a la progressiva posada en marxa de serveis d'alta qualitat com la televisió d'Ultra AD (Alta Definició). La transició a l'estàndard europeu de segona generació DVB-T2 i la introducció de la codificació de vídeo MPEG-4/AVC ja permet la transmissió de 4-5 serveis de televisió d'AD per canal RF (Radiofreqüència). No obstant això, la impossibilitat d'assignar una major taxa de bit sobre l'espectre restant podria posar en perill l'evolució de les plataformes de TDT en favor d'altres sistemes d'alta capacitat com ara el satèl·lit o les distribuïdores de cable. El següent pas se centra en el desplegament del recent estàndard HEVC (High Efficiency Vídeo Coding), que oferix un 50% de guany de codificació respecte a AVC, junt amb els estàndards terrestres de pròxima generació, la qual cosa podria garantir la competitivitat de la TDT en un futur pròxim. Aquesta tesi aborda l'ús de tecnologies d'agregació de canals RF que permeten incrementar l'eficiència espectral de les futures xarxes. La tesi se centra entorn de dues tecnologies: Time Frequency Slicing (TFS) i Channel Bonding (CB). TFS i CB consistixen en la transmissió de les dades d'un servei de televisió a través de múltiples canals RF en compte d'utilitzar un sol canal. CB difon les dades d'un servei a través d'uns quants canals RF convencionals formant un RF-Mux. TFS difon les dades a través de ranures temporals en diferents canals RF. Les dades són recuperades de forma seqüencial en el receptor per mitjà de salts en freqüència. La implementació d'aquestes tècniques permet obtindre guanys en capacitat i cobertura. La primera d'elles prové d'una multiplexació estadística (StatMux) de serveis de taxa variable (VBR) més eficient. A més, CB permet augmentar la taxa de pic d'un servei de forma proporcional al nombre de canals així com avantatges al combinar-la amb codificació de vídeo escalable. El guany en cobertura prové d'un millor rendiment RF a causa de la recepció de les dades d'un servei des de diferents canals en lloc de només un que podria estar degradat. De la mateixa manera, és possible obtindre una major robustesa enfront d'interferències ja que la recepció o no d'un servei no depén de si el canal que l'allotja està o no interferit. TFS va ser introduït en primer lloc com un annex informatiu en DVB-T2 (no normatiu) i posteriorment va ser adoptat en DVB-NGH (Next Generation Handheld). TFS i CB han sigut proposades per a la seva inclusió en ATSC 3.0. Encara així, mai han sigut implementades. Les investigacions dutes a terme en esta Tesi empren diverses vessants basades en teoria de la informació per a obtindre els límits de guany, en simulacions de capa física per a avaluar el rendiment en sistemes reals i en l'anàlisi de mesures de camp. Aquestos estudis reporten guanys en cobertura entorn als 4-5 dB amb 4 canals i importants guanys en capacitat encara amb només 2 canals RF. Esta tesi també se centra en els aspectes d'implementació. Els receptors per a CB requerixen un sintonitzador per canal RF agregat. La implementació de TFS amb un sol sintonitzador exigix el compliment de diversos requisit temporals. No obstant això, l'ús de dos sintonitzadors permetria un bon rendiment amb una implementació més rendible amb la reutilització dels actuals xips o la seua introducció junt amb les arquitectures existents que operen amb un doble sintonitzador com ara MIMO (Multiple Input Multiple Output). / Giménez Gandia, JJ. (2015). Improved Spectrum Usage with Multi-RF Channel Aggregation Technologies for the Next-Generation Terrestrial Broadcasting [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/52520 / TESIS

Desde comienzos del siglo XXI, los sistemas de radiodifusión terrestre han sido culpados de un uso ineficiente del espectro asignado. Para aumentar la eficiencia espectral, los organismos de estandarización de TV digital comenzaron a desarrollar la evolución técnica de los sistemas de TDT de primera generación. Entre otros, uno de los objetivos principales de los sistemas de TDT de próxima generación (DVB-T2 y ATSC 3.0) es proporcionar simultáneamente servicios de TV a dispositivos móviles y fijos. El principal inconveniente de esta entrega simultánea son los diferentes requisitos de cada condición de recepción. Para abordar estas limitaciones, se han considerado diferentes técnicas de multiplexación. Mientras que DVB-T2 acomete la entrega simultánea de los dos servicios mediante TDM, ATSC 3.0 adoptó la Multiplexación por División en Capas (LDM). LDM puede superar a TDM y a FDM al aprovechar la relación de Protección de Error Desigual (UEP), ya que ambos servicios, llamados capas, utilizan todos los recursos de frecuencia y tiempo con diferentes niveles de potencia. En el lado del receptor, se distinguen dos implementaciones, de acuerdo con la capa a decodificar. Los receptores móviles solo están destinados a obtener la capa superior, conocida como Core Layer (CL). Para no aumentar su complejidad en comparación con los receptores de capa única, la capa inferior, conocida como Enhanced Layer (EL), es tratada como un ruido adicional en la decodificación. Los receptores fijos aumentan su complejidad, ya que deben realizar un proceso de Cancelación de Interferencia (SIC) sobre la CL para obtener la EL. Para limitar la complejidad adicional de los receptores fijos, las capas de LDM en ATSC 3.0 están configuradas con diferentes capacidades de corrección, pero comparten el resto de bloques de la capa física, incluido el TIL, el PP, el tamaño de FFT, y el GI. Esta disertación investiga tecnologías avanzadas para optimizar el rendimiento de LDM. Primero se propone una optimización del proceso de demapeo para las dos capas de LDM. El algoritmo propuesto logra un aumento de capacidad, al tener en cuenta la forma de la EL en el proceso de demapeo de la CL. Sin embargo, el número de distancias Euclidianas a computar puede aumentar significativamente, conduciendo no solo a receptores fijos más complejos, sino también a receptores móviles más complejos. A continuación, se determina la configuración de piloto ATSC 3.0 más adecuada para LDM. Teniendo en cuenta que las dos capas comparten el mismo PP, surge una contrapartida entre la densidad de pilotos (CL) y la redundancia sobre los datos (EL). A partir de los resultados de rendimiento, se recomienda el uso de un PP no muy denso, ya que ya han sido diseñados para hacer frente a ecos largos y altas velocidades. La amplitud piloto óptima depende del estimador de canal en los receptores (ej., se recomienda la amplitud mínima para una implementación Wiener, mientras que la máxima para una implementación FFT). También se investiga la potencial transmisión conjunta de LDM con tres tecnologías avanzadas adoptadas en ATSC 3.0: las tecnologías de agregación MultiRF, los esquemas de MISO distribuido y los de MIMO colocalizado. Se estudian los potenciales casos de uso, los aspectos de implementación del transmisor y el receptor, y las ganancias de rendimiento de las configuraciones conjuntas para las dos capas de LDM. Las restricciones adicionales de combinar LDM con las tecnologías avanzadas se consideran admisibles, ya que las mayores demandas ya están contempladas en ATSC 3.0 (ej., una segunda cadena de recepción). Se obtienen ganancias significativas en condiciones de recepción peatonal gracias a la diversidad en frecuencia proporcionada por las tecnologías MultiRF. La conjunción de LDM con esquemas de MISO proporciona ganancias de rendimiento significativas en redes SFN para la capa fija con el esquema de Alamouti. / Since the beginning of the 21st century, terrestrial broadcasting systems have been blamed of an inefficient use of the allocated spectrum. To increase the spectral efficiency, digital television Standards Developing Organizations settled to develop the technical evolution of the first-generation DTT systems. Among others, a primary goal of next-generation DTT systems (DVB-T2 and ATSC 3.0) is to simultaneously provide TV services to mobile and fixed devices. The major drawback of this simultaneous delivery is the different requirement of each reception condition. To address these constraints different multiplexing techniques have been considered. While DVB-T2 fulfilled the simultaneous delivery of the two services by TDM, ATSC 3.0 adopted the LDM technology. LDM can outperform TDM and FDM by taking advantage of the UEP ratio, as both services, namely layers, utilize all the frequency and time resources with different power levels. At receiver side, two implementations are distinguished, according to the intended layer. Mobile receivers are only intended to obtain the upper layer, known as CL. In order not to increase their complexity compared to single layer receivers, the lower layer, known as EL is treated as an additional noise on the CL decoding. Fixed receivers, increase their complexity, as they should performed a SIC process on the CL for getting the EL. To limit the additional complexity of fixed receivers, the LDM layers in ATSC 3.0 are configured with different error correction capabilities, but share the rest of physical layer parameters, including the TIL, the PP, the FFT size, and the GI. This dissertation investigates advanced technologies to optimize the LDM performance. A demapping optimization for the two LDM layers is first proposed. A capacity increase is achieved by the proposed algorithm, which takes into account the underlying layer shape in the demapping process. Nevertheless, the number of Euclidean distances to be computed can be significantly increased, contributing to not only more complex fixed receivers, but also more complex mobile receivers. Next, the most suitable ATSC 3.0 pilot configuration for LDM is determined. Considering the two layers share the same PP a trade-off between pilot density (CL) and data overhead (EL) arises. From the performance results, it is recommended the use of a not very dense PP, as they have been already designed to cope with long echoes and high speeds. The optimum pilot amplitude depends on the channel estimator at receivers (e.g. the minimum amplitude is recommended for a Wiener implementation, while the maximum for a FFT implementation). The potential combination of LDM with three advanced technologies that have been adopted in ATSC 3.0 is also investigated: MultiRF technologies, distributed MISO schemes, and co-located MIMO schemes. The potential use cases, the transmitter and receiver implementations, and the performance gains of the joint configurations are studied for the two LDM layers. The additional constraints of combining LDM with the advanced technologies is considered admissible, as the greatest demands (e.g. a second receiving chain) are already contemplated in ATSC 3.0. Significant gains are found for the mobile layer at pedestrian reception conditions thanks to the frequency diversity provided by MultiRF technologies. The conjunction of LDM with distributed MISO schemes provides significant performance gains on SFNs for the fixed layer with Alamouti scheme. Last, considering the complexity in the mobile receivers and the CL performance, the recommended joint configuration is MISO in the CL and MIMO in the EL. / Des de començaments del segle XXI, els sistemes de radiodifusió terrestre han sigut culpats d'un ús ineficient de l'espectre assignat. Per a augmentar l'eficiència espectral, els organismes d'estandardització de TV digital van començar a desenvolupar l'evolució tècnica dels sistemes de TDT de primera generació. Entre altres, un dels objectius principals dels sistemes de TDT de pròxima generació (DVB-T2 i el ATSC 3.0) és proporcionar simultàniament serveis de TV a dispositius mòbils i fixos. El principal inconvenient d'aquest lliurament simultani són els diferents requisits de cada condició de recepció. Per a abordar aquestes limitacions, s'han considerat diferents tècniques de multiplexació. Mentre que DVB-T2 escomet el lliurament simultani dels dos serveis mitjançant TDM, ATSC 3.0 va adoptar la Multiplexació per Divisió en Capes (LDM). LDM pot superar a TDM i a FDM en aprofitar la relació de Protecció d'Error Desigual (UEP), ja que tots dos serveis, cridats capes, utilitzen tots els recursos de freqüència i temps amb diferents nivells de potència. En el costat del receptor, es distingeixen dues implementacions, d'acord amb la capa a decodificar. Els receptors mòbils solament estan destinats a obtenir la capa superior, coneguda com Core Layer (CL). Per a no augmentar la seua complexitat en comparació amb els receptors de capa única, la capa inferior, coneguda com Enhanced Layer (EL), és tractada com un soroll addicional en la decodificació. Els receptors fixos augmenten la seua complexitat, ja que han de realitzar un procés de Cancel·lació d'Interferència (SIC) sobre la CL per a obtenir l'EL. Per a limitar la complexitat addicional dels receptors fixos, les capes de LDM en ATSC 3.0 estan configurades amb diferents capacitats de correcció, però comparteixen la resta de blocs de la capa física, inclòs el TIL, el PP, la grandària de FFT i el GI. Aquesta dissertació investiga tecnologies avançades per a optimitzar el rendiment de LDM. Primer es proposa una optimització del procés de demapeo per a les dues capes de LDM. L'algoritme proposat aconsegueix un augment de capacitat, en tenir en compte la forma de l'EL en el procés de demapeo de la CL. No obstant açò, el nombre de distàncies Euclidianes a computar pot augmentar significativament, conduint NO sols a receptors fixos més complexos, sinó també a receptors mòbils més complexos. A continuació, es determina la configuració de pilot ATSC 3.0 més adequada per a LDM. Tenint en compte que les dues capes comparteixen el mateix PP, es produeix una contrapartida entre la densitat de pilots (CL) i la redundància sobre les dades (EL). A partir dels resultats de rendiment, es recomana l'ús d'un PP no gaire dens, ja que ja han sigut dissenyats per a fer front a ecos llargs i altes velocitats. L'amplitud pilot òptima depèn de l'estimador de canal en els receptors (ex., es recomana l'amplitud mínima per a una implementació Wiener, mentre que la màxima per a una implementació FFT). També s'investiga la potencial transmissió conjunta de LDM amb tres tecnologies avançades adoptades en ATSC 3.0: les tecnologies d'agregació de MultiRF, els esquemes de MISO distribuït i els de MIMO colocalitzat. S'estudien els potencials casos d'ús, els principals aspectes d'implementació del transmissor i el receptor, i els guanys de rendiment de les configuracions conjuntes per a les dues capes de LDM. Les restriccions addicionals de combinar LDM amb les tecnologies avançades es consideren admissibles, ja que les majors demandes ja estan contemplades en ATSC 3.0 (ex., una segona cadena de recepció). S'obtenen guanys significatius per a la capa mòbil en condicions de recepció per als vianants gràcies a la diversitat en freqüència proporcionada per les tecnologies MultiRF. La conjunció de LDM amb esquemes MISO distribuïts proporciona guanys de rendiment significatius en xarxes SFN per a la capa fixa amb l'esquema d'Alamouti. / Garro Crevillén, E. (2018). Advanced Layered Divsion Multiplexing Technologies for Next-Gen Broadcast [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/105559 / TESIS

<div>The present thesis was completed to satisfy two functions in our laboratory: (1) explore carbon-black (CB) as an additive for electrodeposited intrinsically conductive polymers (ICPs) to improve electrical properties across the electrode-electrolyte interface for use in neuromodulation; and (2) design a histology protocol that will analyze peripheral nerve system (PNS) tissue following implantation of conventional metal and modified conventional metal electrodes with the ICP poly(3,4-ethylenedioxythiophere):poly(styrenesulfonate)/carbon-black (PEDOT:PSS/CB). It would appear that the functions explored may seem unrelated, however, these two topics play a crucial role in designing a viable electrode for use in acute and chronic neuromodulation and the subsequent analysis required to determine the mechanical properties and overall biocompatibility of design.</div><div><br></div><div><div>A series of experiments with different PEDOT:PSS solutions containing varying amounts of suspended CB (n=19; 0 mg/mL to 2 mg/mL) were explored. Solutions were characterized using cyclic voltammetry (CV) using the intended electrode for deposition, composed of stainless steel (SS), as the working electrode (WE) to determine respective redox potentials. SS was chosen because of its inherently bad electrochemical properties, meaning that improved functionality post electrodeposition would be easy to identify. Immediately following CV, stainless-steel electrodes were electrodeposited using one of two techniques: (1) potentiostat, allowing the cell to rest at the redox potential required for bipolaron formation (0.9 V); or (2) galvanostat, where the electrode was submitted to a constant current of 200 mA and allowed to coat. Rapid electrochemical impedance spectroscopy was performed prior to and immediately following coating to determine the pre-electrochemical and post-electrochemical impedance characteristics. Results indicate that there was a positive relationship between the amount of CB additive and the relative impedance drop between the uncoated and coated counterparts. Furthermore, the modified electrochemical interfaces are substantially improved for use in frequency ranges of 10 Hz to 50 kHz, which encompass the ranges of our labs recently discovered low frequency alternating current (LFAC) for use in neuromodulation; thus indicating that PEDOT:PSS/CB modification may be used to improve impedance characteristics during our future LFAC experiments. This protocol, the one that contains the ideal concentration of carbon-black, was then recorded and will be used in our lab.</div></div><div><br></div><div><div>Histology protocols were developed to improve our labs capabilities of post-mortem analysis of PNS tissue. Processing and embedding preparations that explored included paraffin, acrylic, and frozen. Subsequently, staining protocols were developed; however, they varied as a function of the embedding media used; staining protocols developed incorporated progressive and regressive hematoxylin and eosin (H&E) staining as well as toluidine blue (TB). Tissue was sectioned and observed using light microscopy.</div></div>

Der Tod einer Person (ein Ereignis) und ihre Sterblichkeit (eine Eigenschaft) sind nicht dasselbe, hängen aber klarerweise zusammen. Angenommen der Tod einer Person ist schlecht für diese – was bedeutet dies dann für die Bewertung ihrer Sterblichkeit? Um diese Frage zu beantworten muss unterschieden werden zwischen zwei verschiedenen Arten von Sterblichkeit: Die kontingente Sterblichkeit („sterben können“) ist die dispositionale Eigenschaft eines Lebewesens unter bestimmten Umständen zu sterben. Der Tod des Lebewesens ist die Manifestation dieser Disposition. Die notwendige Sterblichkeit andererseits („sterben müssen“) ist die (Meta-)Eigenschaft eines Lebwesens eine begrenzte Lebenserwartung zu haben – das heißt, eine Disposition zu sterben zu haben, die notwendigerweise irgendwann manifestiert wird. Der werttheoretische Zusammenhang zwischen Tod und Sterblichkeit ergibt sich plausiblerweise aus den Rollen, die kontingente und notwendige Sterblichkeit beim Zustandekommen des Todes einer Person spielen: Es zeigt sich, dass die Disposition zu sterben den Tod der Person ermöglicht. Dadurch macht sie einen kausal relevanten Unterschied im Auftreten eines für diese Person schlechten Ereignisses und beeinflusst so ihr Wohlergehen. Deshalb ist die kontingente Sterblichkeit schlecht für die Person – und diese Schlechtigkeit erbt sie von dem Ereignis des Todes. Steht dieses Ereignis allerdings noch nicht fest, erbt die kontingente Sterblichkeit stattdessen einen Teil des erwarteten Unwerts des Todes. Die notwendige Sterblichkeit andererseits erbt einen Teil des generellen Unwerts des Todes (verstanden als Ereignistyp), weil sie das Eintreten eines solchen Ereignisses vorwegnimmt, indem sie garantiert, dass ein Ereignis dieses Typs eintreten muss. Gleichzeitig scheint die notwendige Sterblichkeit ihrerseits die Evaluation des Todes (und somit auch der kontingenten Sterblichkeit) zu beeinflussen: Der Tod einer Person wirkt weniger tragisch, wenn sie notwendig sterblich ist. / The death of a person (an event) and her mortality (a property) are not the same but nevertheless clearly related. Assuming that a person’s death is bad for her, one may ask what this would mean for the evaluation of her mortality. To answer this question, one must distinguish between two different kinds of mortality: Contingent mortality (“being able to die”) is the dispositional property of a living being to die under certain circumstances. The death of the being is the manifestation of this disposition. Necessary mortality on the other hand (“having to die”) is the (meta-)property of a living being to have a limited life-expectancy, that is, to have a disposition to die that is necessarily manifested eventually. The evaluative connection between death and mortality can plausibly be derived from the roles that a person’s contingent and necessary mortality play in the occurrence of her death: It turns out that the disposition to die is an enabling condition for the person’s death. This means that it makes a causally relevant difference in the occurrence of an event that is bad for the person and thereby genuinely and negatively affects her wellbeing. Therefore, her contingent mortality is bad for the person – and this badness is derived from the badness of the event of her death. If this event is not yet settled, the contingent mortality inherits a part of the expected disvalue of the person’s death instead. Her necessary mortality on the other hand inherits part of the general disvalue of the person’s death (understood as a type of event) because it anticipates the occurrence of such an event by guaranteeing that an event of this type must occur. At the same time, the presence of a person’s necessary mortality seems to affect the evaluation of her death (and thereby also her contingent mortality): A person’s death appears less tragic if she is necessarily mortal.

English speakers use the concept of "darkness" in a number of metaphors to portray a wide variety of experiences from evil to fear to ignorance. These metaphorical connections or entailments are so natural that we can see an image of a dark-clad person in a film or book and usually be correct in assuming that they are at best questionably moral and at worst a villain. The Old Testament (OT) also employs dark images and dark imagery to various effects. From Job's description of the underworld in Job 3 to Isaiah 's description of the coming light that will dispel the darkness in Isa 8- 9, to the dark paths the wicked trod in Eccl 2:14, the OT uses a number of metaphors of darkness. For most of these examples, it would be easy to assume that the ancient Hebrew writers of the OT were working with the same concepts of darkness that we do today and thus interpret these passages along the same lines as our own modem English metaphors. But such assumptions can and have led to a number of misunderstandings and conflicting interpretations of passages that employ dark images. These miscommunications are most apparent in passages where God's presence is indicated by darkness like at the Sinai and Temple theophanies (Exod 20:19-20 and 1 Kgs 8:12, respectively) as well as later poetry about God (Ps 97:2). By combining the theoretical framework of Cognitive Metaphor Theory (CMT), and the methodology of Conceptual Blending (CB), this study will work toward a clearer understanding of how the writers of the OT understood darkness and how that shaped their use of it in their images and imagery of death, captivity, the unknowable, and God. It will be shown that the ancient Hebrew conception and use of darkness centres around three key recurring metaphors - Death is Darkness, Captivity is Darkness, and the Unknown is Darkness - while the metaphor Evil is Darkness is foreign to the OT. These findings serve to provide greater clarity in interpreting those OT passages that portray God as having a penchant for darkness.

CATD was not only adequate for analyzing the pursuit of erratically moving prey but also worked well when analyzing the pursuit of prey that remained stationary. It cannot be fully concluded that bats utilize the CATD strategy to successfully capture erratically flying prey. The angle remains relatively constant but does not exhibit a zero change in angle as by definition. The large forces experienced by the bat were seen when the bat began to rotate its body about its pitch axis or when the bat made a large turn. Moments were seen specifically when the bat began to bank into its last and final turn towards its target.; Digital recordings of three different species of bats were studied in this thesis to determine the forces and moments that were experienced throughout the bat's flight. The recordings were also studied to determine the pursuit strategies that were most effective for the bat to quickly capture its prey. A pursuit strategy is a strategic way to travel that will allow a pursuer to capture/approach their target the quickest. Therefore when a bat utilizes a particular pursuit strategy, it will adjust its position/ direction vector in a particular way that will allow it to approach its target very quickly. Data was collected directly from the video by manual collection utilizing Microsoft Visual Studio to extract frames, collect and record the data. This research was conducted to determine when throughout the flight the bat would experience significant forces and moments. The location and magnitude of the forces were reported along with an explanation of why the bat was experiencing a peak at each specific time. The forces and moments that the bat experienced thought-out the flight pursuit were calculated by relative velocity and acceleration calculations. In all four scenarios the bat experienced forces in relation to rotating its body about its center of mass. Forces were specifically seen when the bat periodically began to rotate its body before the final plunge to capture its prey. Prey avoidance and pursuit strategies were also studied and observed in this thesis which included the constant bearing and the constant absolute target direction. The intent was to determine which pursuit strategy bats use to quickly capture their prey. The constant bearing strategy is utilized to pursue prey moving along a smooth path, on the other hand the Constant Absolute Target Direction (CATD) pursuit strategy is utilized to capture erratically moving prey. For most of the bats analyzed, it was seen that the CATD strategy proved to be the preferred pursuit strategy.

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This Creative Writing PhD consists of a novel, The Encyclopaedia of Istanbul, and accompanying critical essays, Ottoman Crossroads: Coffeehouses, Politics, Theatres and Storytelling. The Encyclopaedia of Istanbul is historical in nature, and magically real in temperament. It is an account of fin de siècle Constantinopolis, and contains forgotten fairy tales, remnants of an ancient manuscript culture, Armenian playwrights, Turkish feminists, Greek fortune-tellers and Sephardim cantors. It tells the tale of six intersecting lives in 1876, a time known as “the year of the three Sultans” in Ottoman history. This period was filled with tensions between traditionalism and Westernization, but also new political possibilities forwarded by the Young Ottomans. While the characters in The Encyclopaedia of Istanbul are fictitious, they are inspired by historical events and figures. The second element of my PhD, Ottoman Crossroads, is made up of four individual essays that focus on selected themes from the novel. They scrutinize, in order of presentation, the history of coffeehouse culture, the secretive society of the Young Ottomans and their political thought, the formation of Armenian-Turkish theatre, and the rediscovery of Ottoman fairy tales. Whilst the novel and essays are coherent independently, they also link to each other in ways that are sometimes direct, and at other times subtle.

The objective of my work was to develop HDPE clay nanocomposites for packaging with superior barrier (gas and water) properties by economical processing technique. This work also represents a comparative study of thermoplastic nanocomposites for packaging based on linear low density polyethylene (LLDPE), high density polyethylene (HDPE) and Nylon12. In this study properties and processing of a series of linear low density polyethylene (LLDPE), high density polyethylene (HDPE) and Nylon 12 nanocomposites based on Na-MMT clay and two different aspect ratio grades of kaolinite clay are discussed.