Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-08-16T20:20:26Z No. of bitstreams: 1 AtilaVarelaFerreiraMedeirosDeOliveira_DISSERT.pdf: 1603393 bytes, checksum: dca520d8a49b825f11ed063f8807d7f1 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-08-18T00:33:44Z (GMT) No. of bitstreams: 1 AtilaVarelaFerreiraMedeirosDeOliveira_DISSERT.pdf: 1603393 bytes, checksum: dca520d8a49b825f11ed063f8807d7f1 (MD5) / Made available in DSpace on 2016-08-18T00:33:44Z (GMT). No. of bitstreams: 1 AtilaVarelaFerreiraMedeirosDeOliveira_DISSERT.pdf: 1603393 bytes, checksum: dca520d8a49b825f11ed063f8807d7f1 (MD5) Previous issue date: 2015-12-07 / Este trabalho prop?e uma nova estrat?gia de navega??o aut?noma assistida por algoritmo gen?tico com planejamento din?mico para rob?s m?veis terrestres, chamada DPNA-GA (Dynamic Planning Navigation Algorithm optimized with Genetic Algorithm). A estrat?gia foi aplicada em ambientes - tanto est?ticos, quanto din?micos - nos quais a localiza??o e o formato dos obst?culos n?o s?o previamente conhecidos. A cada evento de deslocamento, uma nova rota ? planejada atrav?s de um algoritmo que minimiza a dist?ncia entre o rob? e o objetivo e maximiza a dist?ncia em rela??o aos obst?culos. Utilizando um sensor de localiza??o espacial e um conjunto de sensores de dist?ncia, a estrat?gia de navega??o proposta foi capaz de planejar dinamicamente percursos ?timos livres de colis?o. Simula??es realizadas em diferentes ambientes demostraram que a t?cnica fornece um alto grau de flexibilidade e robustez. Para isso, foram aplicadas diversas varia??es de par?metros gen?ticos, tais como: taxa de cruzamento, tamanho da popula??o, dentre outros. Finalmente, os resultados das simula??es demonstram satisfatoriamente a efic?cia e robustez da t?cnica DPNA-GA, validando-a para aplica??es reais em rob?s m?veis terrestres. / This work proposes a new autonomous navigation strategy assisted by genetic algorithm with dynamic planning for terrestrial mobile robots, called DPNA-GA (Dynamic Planning Navigation Algorithm optimized with Genetic Algorithm). The strategy was applied in environments - both static and dynamic - in which the location and shape of the obstacles is not known in advance. In each shift event, a control algorithm minimizes the distance between the robot and the object and maximizes the distance from the obstacles, rescheduling the route. Using a spatial location sensor and a set of distance sensors, the proposed navigation strategy is able to dynamically plan optimal collision-free paths. Simulations performed in different environments demonstrated that the technique provides a high degree of flexibility and robustness. For this, there were applied several variations of genetic parameters such as: crossing rate, population size, among others. Finally, the simulation results successfully demonstrate the effectiveness and robustness of DPNA-GA technique, validating it for real applications in terrestrial mobile robots.

Submitted by Jos? Henrique Henrique (jose.neves@ufvjm.edu.br) on 2017-06-22T22:29:53Z No. of bitstreams: 2 everton_oliveira_paiva.pdf: 3688473 bytes, checksum: 00c67bcc4d4564b69bb64a0b596743fc (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2017-06-23T13:21:09Z (GMT) No. of bitstreams: 2 everton_oliveira_paiva.pdf: 3688473 bytes, checksum: 00c67bcc4d4564b69bb64a0b596743fc (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-06-23T13:21:09Z (GMT). No. of bitstreams: 2 everton_oliveira_paiva.pdf: 3688473 bytes, checksum: 00c67bcc4d4564b69bb64a0b596743fc (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2016 / O uso sistemas computacionais como complemento ou substitui??o da sala de aula ? cada vez mais comum na educa??o e os Sistemas Tutores Inteligentes (STIs) s?o uma dessas alternativas. Portanto ? fundamental desenvolver STIs capazes tanto de ensinar quanto aprender informa??es relevantes sobre o aluno atrav?s de t?cnicas de intelig?ncia artificial. Esse aprendizado acontece por meio da intera??o direta entre o STI e o aluno que ? geralmente demorada. Esta disserta??o apresenta a inser??o da metaheur?sticas Lista Tabu e GRASP com o objetivo de acelerar esse aprendizado. Para avaliar o desempenho dessa modifica??o, foi desenvolvido um simulador de STI. Nesse sistema, foram realizadas simula??es computacionais para comparar o desempenho da tradicional pol?tica de explora??o aleat?ria e as metaheur?sticas propostas Lista Tabu e GRASP. Os resultados obtidos atrav?s dessas simula??es e os testes estat?sticos aplicados indicam fortemente que a introdu??o de meta-heur?sticas adequadas melhoram o desempenho do algoritmo de aprendizado em STIs. / Disserta??o (Mestrado Profissional) ? Programa de P?s-Gradua??o em Educa??o, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2016. / Using computer systems as a complement or replacement for the classroom experience is an increasingly common practice in education and Intelligent Tutoring Systems (ITS) are one of these alternatives. Therefore, it is crucial to develop ITS that are capable of both teaching and learning relevant information about the student through artificial intelligence techniques. This learning process occurs by means of direct, and generally slow, interaction between the ITS and the student. This dissertation presents the insertion of meta-heuristic Tabu search and GRASP with the purpose of accelera ting learning. An ITS simulator was developed to evaluate the performance of this change. Computer simulations were conducted in order to compare the performance of traditional randomized search methods with the meta-heuristic Tabu search. Results obtained from these simulations and statistical tests strongly indicate that the introduction of meta-heuristics in exploration policy improves the performance of the learning algorithm in ITS.

Abstract The next-generation networks are set to support a high data rate, low latency, high reliability, and diverse types of services and use cases. These requirements come at the expense of a more complex network management, and asymmetric and time-varying traffic dynamics. Accordingly, future networks will operate at different duplexing modes and with multiple access techniques. This thesis proposes novel transmission strategies and methodologies to dynamically optimize the duplexing modes and allocate resources for small cell based cellular networks. The first part of the thesis studies dynamic time-division-duplex (TDD) operation in dynamic and asymmetric uplink (UL) and downlink (DL) traffic conditions. In this regard, we propose a dynamic TDD framework that optimizes the UL and DL frame configuration and power allocation. Due to the high interference coupling between neighboring small cells, we propose a load-aware clustering method that groups the small cell base stations (SBSs) based on their spatial and load similarities. To balance the UL and DL loads within each cluster, we study the potential of load-based UL/DL decoupled user association in balancing the traffic loads within clusters. In the second part, we study the problem of half-duplex (HD)/full-duplex (FD) mode selection and UL/DL resource and power optimization in small cell networks. Therein, SBSs operate in non-orthogonal multiple access (NOMA) in both UL and DL to schedule multiple users at the same time-frequency resource. The goal of the study is therefore to select the optimal duplexing and multiple access scheme, based on the traffic load and interference conditions, such that users’ data rates are maximized, while stabilizing traffic queues. Finally, the last part of the thesis looks beyond rate maximization and focuses on ensuring low latency and high reliability in small cell networks providing edge computing services. The problem of distributing wireless resources to users requesting edge computing tasks is cast as a delay minimization problem under stringent reliability constraints. The study investigates the role of proactive computing in ensuring low latency edge computing, while the concept of hedged requests is presented as an enabler for computing service reliability. / Tiivistelmä Seuraavan sukupolven verkot suunnitellaan tukemaan suuria tiedonsiirtonopeuksia, pientä latenssia, erinomaista luotettavuutta ja monentyyppisiä palveluja ja käyttötapauksia. Näiden vaatimusten täyttämisen kääntöpuolena ovat entistä monimutkaisemmat verkonhallintatoiminnot sekä epäsymmetrinen ja ajallisesti muuttuva dataliikenteen dynamiikka. Verkot toimivat tulevaisuudessa eri dupleksointitiloissa hyödyntämällä useita eri liittymätekniikoita. Tässä tutkielmassa ehdotetaan uusia siirtostrategioita ja menetelmiä dupleksointitilojen dynaamista optimointia ja resurssien allokointia varten piensoluperustaisissa solukkoverkoissa. Tutkielman alkuosassa tarkastellaan dynaamisen aikajakodupleksin (TDD) toimintaa dataliikenneympäristöissä, joissa on käytössä dynaaminen ja epäsymmetrinen lähetysyhteys (UL) ja laskeva siirtotie (DL). Ehdotamme tältä osin dynaamista TDD-kehystä, joka optimoi UL- ja DL-kehyksen konfiguroinnin ja tehon allokoinnin. Vierekkäisten pienten solujen välisten kytkösten suuren interferenssin takia ehdotamme kuormituksen huomioivaa klusterointimenetelmää, jossa piensolutukiasemat (SBS) ryhmitellään niiden tilallisten ja kuormitusominaisuuksien yhteneväisyyden perusteella. Tutkimme UL- ja DL-kuormitusten tasapainottamista kussakin klusterissa tarkastelemalla UL/DL-yhteyksistä irti kytketyn, kuormitukseen perustuvan käyttäjän yhdistämisen mahdollisuuksia dataliikennekuormituksen tasapainottamisessa. Tutkielman toisessa osassa tarkastellaan puolidupleksi (HD)- ja kaksisuuntaisen (FD) -tilan valinnan ongelmaa ja UL-/DL-resurssien ja tehon optimointia piensoluverkoissa. Siinä piensolutukiasemat toimivat ei-ortogonaalisessa moniliittymässä (NOMA) sekä UL- että DL-yhteyksissä useiden käyttäjien ajoittamiseksi samalle aika-taajuusresurssille. Tutkielman tavoitteena on siten valita optimaalinen dupleksointi- ja moniliittymäkaavio dataliikenteen kuormituksen ja interferenssin perusteella siten, että käyttäjän tiedonsiirtonopeudet voidaan maksimoida ja dataliikennejonot tasata. Lopuksi tutkielman viimeisessä osassa tarkastellaan tiedonsiirtonopeuden maksimoinnin lisäksi pienen latenssin ja suuren luotettavuuden varmistamista piensoluverkoissa, jotka tuottavat reunalaskentapalveluja. Langattomien resurssien jakelemista käyttäjille, jotka vaativat reunalaskentatehtäviä, käsitellään viiveen minimoinnin ongelmana soveltamalla tiukkoja luotettavuusrajoituksia. Tutkielmassa tarkastellaan proaktiivisen tietojenkäsittelyn roolia pienen latenssin reunalaskennassa.

5G är något som växer fram i samhällen över hela världen. Många stormakter så som USA och Ryssland satsar mycket pengar på att skapa användningsområden för 5G, inte minst i militära sammanhang. Sverige använder idag inte 5G i militära sammanhang. Totalförsvarets forskningsinstitut FOI har dock publicerat rapporter om tänkbara användningsområden för 5G i den militära verksamheten. Detta arbete tar det ett steg längre och ser till hur 5G kan nyttjas specifikt i stridslednings- och luftbevakningsbataljonen. Arbetet har en teknisk utgångspunkt och använder teorin militär nytta. Genom att presentera och analysera sju olika funktioner i 5G. Dessa är mjukvarudefinierande nät, multiantennsystem, self-interference cancellation, hantering av flera samtidiga användare, bredbandiga mottagare och millimetervåg, multikonnektivitet vid flera bärvågor och felrättande kodning. Slutsatsen är att 5G mycket väl kan nyttjas i stridslednings- och luftbevakningsbataljonen. Många av funktionerna passar väl in i bataljonens uppgifter och system. Dock skulle det krävas en omfattande ombyggnation av den befintliga arkitekturen av system som används idag för att 5G ska vara möjligt att implementera. Anledningen till detta är att stridslednings- och luftbevakningsbataljonens system är system av system och där ett system ej går att byta ut eller lägga till utan att andra system påverkas.

Text in English, with abstracts and keywords in English, Zulu and Xhosa / Link to the dataset (catalogue): https://doi.org/10.25399/UnisaData.14101913.v1 / Digital image editing is rooted in the analog practices of photographic retouching from the late nineteenth century. This study interrogated how novel contributions of new media practice can inform understanding of the relationship between digital and analog media. The study also sought to explore new conceptual avenues in the creation of digital art that incorporates key aspects of both new and traditional media. This study employed a literature review of selected discourses related to new media studies. Specifically, the work of scholars Lev Manovich, Jay David Bolter, Richard Grusin, and Filipe Pais on the interplay between traditional and new media formed the cornerstone of the analysis. These discourses contextualise an analysis of several contemporary case studies of digital artists, with a particular focus on John Craig Freeman and the Oddviz collective. These works were selected for the way in which they destabilise conventional notions of digital photography in new media and the way digital content can be ‘displaced’ into a physical space. From this analysis several concepts arise that serve as distinguishing markers for media displacement. These themes include embodiment, memory, identity formation, autotopography, and intermediality. The dissertation concludes with an overview of my work that incorporates the concepts derived from my analysis of the case studies. It discusses how my exhibition Digital Tourist, a mixed media installation, makes use of photogrammetry and AR to displace the private connections of an individual life into the public space of the gallery. / Ukuhlelwa kwezithombe zezindaba zedijithali kususelwe emikhubeni ye-analokhu yokuthwebula kabusha izithombe kusukela ngasekupheleni kwekhulu leshumi nesishiyagalolunye leminyaka.. Lolu cwaningo luphenye ukuthi iminikelo yenoveli emisha yokwenziwa kwezezindaba ezintsha zingakwazisa kanjani ukuqonda kobudlelwano phakathi kwezindaba zedijithali ne-analokhu. Ucwaningo luphinde lwafuna ukubheka izindlela ezintsha zomqondo ekwakhiweni kobuciko bedijithali obufaka izinndaba ezibalulekile kokubili kwezokuxhumana nezendabuko ezintsha. Izinkulumo ezikhethiwe ezihlobene nezifundo zezindaba ezintsha zibuyekeziwe. Ngokuqondile, umsebenzi wezazi uLev Manovich, Jay David Bolter, Richard Grusin noFilipe Pais ekusebenzisaneni phakathi kwabezindaba bendabuko nabasha kwakha okuzobhekwa ngqo uma kuhlaziywa. Lezi zinkulumo zigxila ekuhlaziyweni kwezifundo zamanje zamaciko edijithali, kugxilwe kakhulu kuJohn Craig Freeman kanye neqoqo le-Oddviz. Le misebenzi yakhethwa ngendlela yokuthi ingazinzisi imiqondo ejwayelekile yokuthwebula izithombe zedijithali emithonjeni emisha kanye nokuthi okuqukethwe kwedijithali "kungahanjiswa kanjani" endaweni ebonakalayo. Ukusuka kulokhu kuhlaziywa kuvela imiqondo eminingana esebenza njengezimpawu ezihlukanisayo zokufuduswa kwabezindaba. Lezi zingqikithi zifaka phakathi ukwakheka, inkumbulo, ukwakheka kobunikazi, ukuziphendulela kanye nokuzibandakanya. Idezetheyishini iphetha ngokubuka konke ngomsebenzi wami ohlanganisa imiqondo esuselwe ekuhlaziyweni kwami kwezifundo zocwaningo. Ingxoxo ihlanganisa ukuthi umbukiso wami we-Zivakashi zeDijithali, ukufakwa kwabezindaba okuxubile, isebenzisa uhlelo lokuthwebula olusebenzisa ulimi noma ifothogrametri ne-AR ukukhipha ukuxhumana kwangasese kwempilo yomuntu ngamunye endaweni yomphakathi yegalari. / Ukuhlela imifanekiso yedijithali yinkqubo eyendeleyo, nowaqalwa kwiminyaka yokugqibela yenkulungwane yeshumi elinethoba, kwimisebenzi yezifaniso/yeanalogu ekuhlaziyweni kweefoto. Esi sifundo siphonononga ukuba igalelo elikhethekileyo leendlela ezintsha zonxibelelwano lwemiboniso/imidiya lingenza njani ukuqinisa ukuqonda unxulumano phakathi kwemiboniso yedijithali neyeanalogu. Kwakhona, esi sifundo sizama ukuphanda iindlela ezintsha ezisetyenziswa kubugcisa bedijithali neziquka imiba ephambili yemiboniso yale mihla neyakudala. From this analysis several concepts arise that serve as distinguishing markers for media displacement. These themes include embodiment, memory, identity formation, autotopography and intermediality. Kuphononongwe iingxoxo ezithile ezimalunga nezifundo zemiboniso yale mihla. Kuqwalaselwe ngakumbi imisebenzi yeengcali ooLev Manovich, Jay David Bolter, Richard Grusin kunye noFilipe Pais malunga nonxulumano phakathi kwemiboniso yakudala neyale mihla njengesiseko solu hlalutyo. Ezi ngxoxo zifaka emxholweni uhlalutyo lwezifundo zokuzekelisa zale mihla malunga nabazobi bale mihla, kugxininiswa kwindibanisela ka John Craig Freeman nekaOddviz. Le misebenzi ikhethwe ngenxa yokuba iyazichitha iingcinga eziqhelekileyo malunga nokufota ngedijithali kwimiboniso yale mihla nangendlela iziqulatho zedijithali “zinokushenxiswa” zisiwe kwindawo ebambekayo. Olu hlalutyo luveze iingcinga eziliqela nezisebenza njengeempawu zoshenxiso lwemiboniso. Imixholo iquka imifuziselo, ukukhumbula, ukwenziwa kwesazisi, ukuzazisa ngezinto onazo, unxulumano phakathi kwemiboniso eyahlukeneyo Le ngxelo yophando igqibela ngokushwankathela umsebenzi wam ohlanganisa iingcinga ezivele ekuhlalutyeni kwam izifundo ezingumzekelo. Ingxoxo ibonisa ukuba umboniso wengqokelela yemisebenzi yam owaziwa ngokuba yiDigital Tourist, ubusebenzise njani ubuchwepheshe ekuthiwa yifotogrametri (obokufumana ulwazi ngokuhlalutya imifanekiso) ekushenxiseni unxulumano lwabucala lobomi bomntu ibubeke kwindawo ebonwa nguwonkewonke apho kubukwa imifanekiso neefoto (igalari). / https://doi.org/10.25399/UnisaData.14101913.v1 / Arts and Music / M.A. (Visual Arts)

Made available in DSpace on 2015-03-03T15:08:47Z (GMT). No. of bitstreams: 1 BrunoSJC_TESE.pdf: 2605632 bytes, checksum: cc7fdbd9d8d7dfe3adac23f17fab1ae2 (MD5) Previous issue date: 2014-05-13 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / In this work, we propose a two-stage algorithm for real-time fault detection and identification of industrial plants. Our proposal is based on the analysis of selected features using recursive density estimation and a new evolving classifier algorithm. More specifically, the proposed approach for the detection stage is based on the concept of density in the data space, which is not the same as probability density function, but is a very useful measure for abnormality/outliers detection. This density can be expressed by a Cauchy function and can be calculated recursively, which makes it memory and computational power efficient and, therefore, suitable for on-line applications. The identification/diagnosis stage is based on a self-developing (evolving) fuzzy rule-based classifier system proposed in this work, called AutoClass. An important property of AutoClass is that it can start learning from scratch". Not only do the fuzzy rules not need to be prespecified, but neither do the number of classes for AutoClass (the number may grow, with new class labels being added by the on-line learning process), in a fully unsupervised manner. In the event that an initial rule base exists, AutoClass can evolve/develop it further based on the newly arrived faulty state data. In order to validate our proposal, we present experimental results from a level control didactic process, where control and error signals are used as features for the fault detection and identification systems, but the approach is generic and the number of features can be significant due to the computationally lean methodology, since covariance or more complex calculations, as well as storage of old data, are not required. The obtained results are significantly better than the traditional approaches used for comparison / Este trabalho prop?e um algoritmo de dois estagios para detec??o e identifica??o de falhas, em tempo real, em plantas industriais. A proposta baseia-se na analise de caracter?sticas selecionadas utilizando estimativa de densidade recursiva e um novo algoritmo evolutivo de classifica??o. Mais especificamente, a abordagem proposta para detec??o e baseada no conceito de densidade no espa?o de dados, o que difere da tradicional fun??o densidade de probabilidade, porem, sendo uma medida bastante util na detec??o de anormalidades/outliers. Tal densidade pode ser expressa por uma fun??o de Cauchy e calculada recursivamente, o que torna o algoritmo computacionalmente eficiente, em termos de processamento e memoria, e, dessa maneira, apropriado para aplica??es on-line. O estagio de identifica??o/diagnostico e realizado por um classificador baseado em regras fuzzy capaz de se auto-desenvolver (evolutivo), chamado de AutoClass, e introduzido neste trabalho. Uma propriedade importante do AutoClass e que ele e capaz de aprender a partir do zero". Tanto as regras fuzzy, quanto o numero de classes para o algoritmo n?o necessitam de pre-especifica??o (o numero de classes pode crescer, com os rotulos de classe sendo adicionados pelo processo de aprendizagem on-line), de maneira n~ao-supervisionada. Nos casos em que uma base de regras inicial existe, AutoClass pode evoluir/desenvolver-se a partir dela, baseado nos dados adquiridos posteriormente. De modo a validar a proposta, o trabalho apresenta resultados experimentais de simula??o e de aplica??es industriais reais, onde o sinal de controle e erro s?o utilizados como caracter?sticas para os estagios de detec??o e identifica??o, porem a abordagem e generica, e o numero de caracter?sticas selecionadas pode ser significativamente maior, devido ? metodologia computacionalmente eficiente adotada, uma vez que calculos mais complexos e armazenamento de dados antigos n?o s?o necess?rios. Os resultados obtidos s?o signifificativamente melhores que os gerados pelas abordagens tradicionais utilizadas para compara??o

Tesis por compendio / 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]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/105559 / Compendio

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Text in German / Summaries in German, English, Afrikaans and Zulu / So vielfältig die Aufgaben sind, sich ehrenamtlich und damit freiwillig und unentgeltlich zu engagieren, so vielfältig sind die Motive, die dabei eine Rolle spielen können. In dieser Forschungsarbeit wird untersucht, welche Motive ausschlaggebend dafür sind, dass leitende Frauen und Männer unterschiedlichsten Alters über Jahre hinweg treu ihren Dienst in einer Einrichtung für suchtkranke Menschen tun und dabei nicht resignieren. Anhand von geführten Leitfaden-Interviews lässt sich dabei erkennen, inwieweit auch christliche Motive eine Grundlage für den ehrenamtlichen Einsatz darstellen. Dazu gibt besonders Joachim Bauer mit seinen neurobiologischen Untersuchungen der menschlichen Motivationssysteme viele Anhaltspunkte. Die durchgeführten Interviews werden mithilfe einer thematischen Inhaltsanalyse bearbeitet und anschließend bewertet. Abschließend werden Vorschläge zum Umgang mit ehrenamtlichen Mitarbeiterinnen und Mitarbeitern in der Suchtkrankenhilfe formuliert. Diese qualitative Studie leistet einen Beitrag dazu, neue Erkenntnisse über die Motivation ehrenamtlicher Suchtkrankenhelfer zu bekommen, was in dieser Form noch nicht erforscht wurde. / Just as varied as the tasks are for unpaid volunteer work, the potential motives are equally as diverse. This research will examine which motives are critical, for women and men of various ages in positions of leadership, to serve faithfully for years in institutions for addicts and not to resign. From guided interviews, it can be seen to what degree Christian motives form a foundation for this volunteer work. Joachim Bauer’s neurobiological research of “human motivation systems” supplies us with key indicators. The interviews will be performed using a method of thematic content analysis and then rated. In conclusion, proposals for handling volunteers working in the area of assisting addicts will be provided. This qualitative study will contribute new insights about the motivation of volunteers in facilities for addicts in an area that is yet to be explored using this approach. / Net so uiteenlopend as wat die take van onbetaalde vrywilligerwerkers is, is die potensiële beweegredes van hierdie vrywilligers. Hierdie navorsing stel ondersoek in na watter beweegredes krities is en daartoe lei dat mans en vroue van verskillende ouderdomme in posisies van leierskap vir jare getrou dien by instellings vir verslaafdes en nie bedank nie. Uit gestruktureerde onderhoude kan gesien word in watter mate Christelike motiewe of beweegredes die fondasie vir hierdie vrywillerwerk is. Joachim Bauer se neurobiologiese navorsing oor “menslike motiveringstelsels” bied aan ons sleutelaanwysers. Die onderhoude sal gevoer word met behulp van ’n metode van tematiese inhoudsontleding, waarna dit gegradeer sal word. Ten slotte sal voorstelle gegee word vir die hantering van vrywilligers wat met verslaafdes werk. Hierdie kwalitatiewe studie sal bydra tot nuwe insigte oor die motivering van vrywilligers in fasiliteite vir verslaafdes op ’n terrein wat nog nie aan die hand van hierdie benadering ontgin is nie. / Njengoba kunemisebenzi ehlukahlukene njengemisebenzi yamavolontiya angakhokhelwa, izisusa zakhona ezibalulekile zibanzi. Lolu cwaningo luzohlola ukuthi iziphi izisusa ezibalulekile, kubantu besilisa nabesifazane abehluka ngeminyaka ezikhundleni zobuholi, abazinikela emsebenzini ngokwethembeka ngokweminyaka abasuke beyibambile ezikhungweni kulabo asebejwayele noma okusegazini kubo okwenza okuthile kodwa bangawuyeka umsebenzi. Kusukela kuyizinhlolokhono eziqondile, kuyabonakala ukuthi yiziphi izizathu zobuKristu ezakha isisekelo salomsebenzi wokuvolontiya. Ucwaningo luka-Joachim Bauer oluqondene nezinzwa noma imizwa "lwezinhlelo zokugqugquzela abantu" lusinikeza izinkomba ezibalulekile. Inhlolokhono ezokwenziwa kuzosetshenziswa indlela yokuhlaziywa okuqukethwe bese ilinganiswa. Uma ngiphetha, iziphakamiso ngokuphatha amalovontiya asuke esebenza endaweni lapho esiza abasuke sebejwayele noma okusegazini kubi okwenza okuthile luzonikwa. Lolu cwaningo olungqala luzofaka ulwazi olusha olumayelana nokugqugquzelwa kwamavolontiya ezindaweni lapho kuhlala abantu asebejwayele noma okusegazini kubo okwenza okuthile okuyindawo esazohlonzwa kusetshenziswa lendlela. / Christian Spirituality, Church History and Missiology / M. Th. (Christian Leadership)