Orientador: Jose Antonio Siqueira Dias / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação / Made available in DSpace on 2018-08-08T10:27:05Z (GMT). No. of bitstreams: 1 Moraes_LucianoCamaraBuenode_M.pdf: 4566206 bytes, checksum: 004300417197b06c786d6cac40898584 (MD5) Previous issue date: 2007 / Resumo: Este trabalho tem como objetivo propor um sistema de baixo custo para conversão de veículos urbanos convencionais para propulsão elétrica. Serão abordadas também, técnicas, de paralelismo de dispositivos semicondutores para altas demandas de potência, motores elétricos, baterias, e sistemas de recarga. De uma maneira geral o projeto apresenta a viabilização de uni kit prático de conversão que permite a Substituição do sistema de tração original (gasolina ou álcool) para o sistema de tração elétrica movido à bateria interna recarregável, para uso urbano que, futuramente, possa ser produzido em larga escala. Os resultados dos modelos teóricos são confrontados com os testes práticos. É apresentado, ao final, um veículo completo, que opera apenas com propulsão elétrica, bem como os íesíes realizados neste veículo / Abstract: The objective of the dissertation is to present a low cost system for the utilization of electric propulsion in urban vehicles powered with internal combustion engines, ft will be discussed semiconductor devices parallelism techniques for high demands of power, electric engines, batteries, and re-charge- systems. In a general way. the project has as objective the design of a conversion kit that allows the substitution of the of original traction of the vehicle by an electric traction system with rechargeable interna! batteries, and that can be produced in large scale. The results of the theoretical models are compared with the practical evaluation tests. The experimental results measured in a complete vehicle assembled using the developed kit are presented / Mestrado / Eletrônica, Microeletrônica e Optoeletrônica / Mestre em Engenharia Elétrica

Orientador: Luiz Carlos Kretly / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação / Made available in DSpace on 2018-08-11T03:07:44Z (GMT). No. of bitstreams: 1 Capovilla_CarlosEduardo_D.pdf: 7813094 bytes, checksum: 52ab9727d246649f4c3628a9a462e9c2 (MD5) Previous issue date: 2008 / Resumo: Esta pesquisa tem por objetivo a concepção de novas topologias de circuitos integrados e suas caracterizações para operação em sistemas de rádio-recepção. O projeto e a fabricação de chaves de RF, LNAs, mixer e VCOs são apresentados. A técnica SMILE (Spatial MultIplexing ofLocal Elements) foi adotada devido às suas vantagens e funcionalidade para a otimização física de antenas inteligentes. Essa técnica requer um chaveamento sequencial das antenas do arranjo e para tal foi desenvolvido um controle de chaveamento acionado por um VCO digital. A demultiplexação analógica do sinal é implementada através de um OTA e chaves analógicas diferenciais. Assim, além da introdução de novas topologias de circuitos integrados, este trabalho estabelece procedimentos de projeto e simulação associados à validação dos dispositivos fabricados. Palavras-chave: circuitos integrados, rádio-recepção, antenas inteligentes, SMILE / Abstract: This research aims the conception of new topologies of integrated circuits and its characterizations for operation in radio-receiver systems. The design and fabrication of RF switches, LNAs, mixer, and VCOs are presented. The SMILE - Spatial MultIplexing of Local Elements - technique was adopted due to its advantages and functionality for the intelligent antennas physical optimization. This technique requires a sequential switching of the antennas and for this purpose a switch driver with a digital VCO was developed. The analog demultiplexation of the signal is implemented with OTA and differential analog switches. Thus, besides the introduction of new integrated circuit topologies, this work establishes procedures of design and simulation together with the manufactured devices validation. Keywords: integrated circuits, radio-reception, smart antennas, SMILE / Doutorado / Eletrônica, Microeletrônica e Optoeletrônica / Doutor em Engenharia Elétrica

Esse trabalho apresenta uma proposta na área de Educação em Microeletrônica que visa enriquecer práticas de ensino adotadas na área de projetos de circuitos integrados através do uso de máquinas de ensino-aprendizagem (TLM Teaching-Learning Machine) em aulas de laboratórios como instrumentos auxiliares e complementares ao ensino teórico. As TLMs propostas permitem a verificação experimental de conceitos fundamentais em VLSI Design, tais como: polarização de transistores NMOS e PMOS, inversores CMOS, curvas de transferência do inversor CMOS, implementação de diversas portas lógicas CMOS estática e dinâmica usando transistores de passagem ou portas de transmissão (NAND, NOR, AND, OR, XOR, XNOR, MUX, DECODER, Half ADDERs e Full ADDERs), Latches, Flip-flops e células de memória (RAM e ROM). A metodologia usada foi baseada em pesquisa bibliográfica, observações em sala de aula, participação em projetos didáticos, entrevistas com alunos e professores de microeletrônica. As TLMs foram construídas na forma de painéis de papelão de 100 cm x 70 cm com eletrônica embarcada ou conjuntos de módulos de circuito impresso com tamanhos A4 até A10, interligados entre si por meio de conectores, cabos elétricos padronizados e acondicionados em caixas flexíveis de borracha sintética. Considerou-se o uso combinado desses materiais com diferentes técnicas de montagens eletrônicas. No leiaute das TLMs foram considerados aspectos da interação homem-máquina (HMI) e projetos de interações por PREECE (2002), e da transposição didática de CHEVALHARD e JOSHUA (1981). Os resultados efetivos da aprendizagem usando TLMs foram obtidos por meio de uma dinâmica em sala de aula baseada no microensino em ALLEN (1967). / This paper presents a proposal in the area of Education in Microelectronics which aims to enrich the educational practices adopted in the area of integrated circuits design through the use of teaching-learning machines (TLM) in classes, laboratories as auxiliary and complementary instruments to the theoretical ones. The proposed TLMs allow the experimental verification of fundamental concepts in VLSI design, such as: NMOS and PMOS transistors biasing, CMOS inverters, transfer curves of a CMOS inverter, implementation of various static and dynamic CMOS logic using the pass-transistor or transmission gates (NAND, NOR, AND, OR, XOR, XNOR, MUX, DECODER, Half ADDERs and Full ADDERs), Latches, flip-flops and memory cells (RAM and ROM). The used methodology was based on a literature search, observations in the classroom, participation in educational projects, interview of students and professors involved with microelectronics. The TLMs were assembled in the form of paper panels, 100 cm x 70 cm embedded with electronic modules, or sets of printed circuit boards with A4 size up to A10 size, connected with each other through connectors, electrical wires and packed in synthetic rubber flexible boxes. The combined use of these materials with different techniques of electronic assemblies has been very important. The layout of TLMs concerns about the aspects of human-machine interaction (HMI) and design interactions from PREECE (2002), and the didactical transposition from CHEVALHARD and JOSHUA (1981). The effective learning results using TLMs were obtained through a dynamic in classroom based on microteaching from ALLEN (1967).

4H-SiC based Metal-Oxide Semiconductor(MOS) capacitors are promising key components for next generation power devices. For high frequency power applications, however, there is a major drawback of this type of devices, i.e. they have low inversion channel mobility that consequently affects the switching operation in MOS Field-Effect Transistors (MOSFETs). Carbon clusters or excess carbon atoms in the interface between the dielectric layer and SiC is commonly considered to be the carrier trapping and scattering centers that lower the carrier channel mobility. Based on the previous work in the research group, a new fabrication process for forming the dielectric layer with a lower density of the trap states is investigated. The process consists of standard semiconductor cleaning, pre-treatments, pre-oxidation, plasma enhanced chemical vapor deposition (PECVD) and post oxidation annealing. I-V measurements of the dielectric strength showed that the resulting layers can sustain proper working condition under an electric field of at least 5MV/cm. C-V characteristics measurements provided the evidence that the proposed method can effectively reduce the interfacial states, which are main culprit for a large flat band voltage shift of C-V characteristics, in particular under annealing at 900°C in nitrogen atmosphere.

Context: Video stabilization techniques have gained popularity for their permit to obtain high quality video footage even in non-optimal conditions. There have been significant works done on video stabilization by developing different algorithms. Most of the stabilization software displays the missing image areas in stabilized video. In the last few years hand-held video cameras have continued to grow in popularity, allowing everyone to easily produce personal video footage. Furthermore, with online video sharing resources being used by a rapidly increasing number of users, a large proportion of such video footage is shared with wide audiences. Sadly such videos often suffer from poor quality as frame vibration in video makes human perception not comfortable. In this research an attempt has been made to propose a robust video stabilization algorithm that stabilizes the videos effectively. Objectives: The main objective of our thesis work is to perform effective motion estimation using SIFT features to calculate the inter frame motion, allowing to find Global Motion Vectors and optimal motion compensation is to be achieved using adaptive fuzzy filter by removing the unwanted shakiness and preserve the panning leading to stabilized video. Methods: In this study three types of research questions are used- Experimentation and Literature review. To accomplish the goal of this thesis, experimentation is carried out for performing video stabilization. Motion estimation is done using feature based motion estimation using SIFT and GMVs are calculated. The intentional motion is filtered using Adaptive fuzzy filter to preserve panning and Motion compensation is performed to wrap the video to its stabilized position. MOS implies the mean scores of the subjective tests performed according to the recommendations of ITU-R BT.500-13 and ITU-T P.910 to analyze the results of our stabilized videos. Results: As a part of results from our work, we have successfully stabilized the videos of different resolutions from experimentation. Performance of our algorithm is found better using MOS. Conclusions: Video Stabilization can be achieved successfully by using SIFT features with pre conditions defined for feature matching and attempts are made to improve the video stabilization process.

This Master Thesis report was written by Umeå University Engineering Physics student Richard Tano during his thesis work at Ericsson Luleå. Monitoring network quality is of utmost importance to network providers. This can be done with models evaluating QoS (Quality of Service) and conforming to ITU-T Recommendations. When determining video stream quality there is of more importance to evaluatethe QoE (Quality of Experience) to understand how the user perceives the quality. This isranked in MOS (Mean opinion scores) values. An important aspect of determining the QoEis the video content type, which is correlated to the coding complexity and MOS values ofthe video. In this work the possibilities to improve quality estimation models complying to ITU-T study group 12 (q.14) was investigated. Methods were evaluated and an algorithm was developed that applies time series analysis of packet statistics for determination of videostreams MOS scores. Methods used in the algorithm includes a novel assembling of frequentpattern analysis and regression analysis. A model which incorporates the algorithm for usage from low to high bitrates was dened. The new model resulted in around 20% improvedprecision in MOS score estimation compared to the existing reference model. Furthermore an algorithm using only regression statistics and modeling of related statistical parameters was developed. Improvements in coding estimation was comparable with earlier algorithm but efficiency increased considerably. / Detta examensarbete skrevs av Richard Tano student på Umeå universitet åt Ericsson Luleå. Övervakning av nätets prestanda är av yttersta vikt för nätverksleverantörer. Detta görs med modeller för att utvärdera QoS (Quality of Service) som överensstämmer med ITU-T rekommendationer. Vid bestämning av kvaliten på videoströmmar är det mer meningsfullt att utvärdera QoE (Quality of Experience) för att få insikt i hur användaren uppfattar kvaliten. Detta graderas i värden av MOS (Mean opinion score). En viktig aspekt för att bestämma QoE är typen av videoinnehåll, vilket är korrelerat till videons kodningskomplexitet och MOS värden. I detta arbete undersöktes möjligheterna att förbättra kvalitetsuppskattningsmodellerna under uppfyllande av ITU-T studygroup 12 (q.14). Metoder undersöktes och en algoritm utvecklades som använder tidsserieanalys av paketstatistik för uppskattning av videoströmmars MOS-värden. Metoder som ingår i algoritmen är en nyutvecklad frekventa mönster metod tillsammans med regressions analys. En modell som använder algoritmen från låg till hög bithastighet definierades. Den nya modellen gav omkring 20% förbättrad precision i uppskattning av MOS-värden jämfört med existerande referensmodell. Även en algoritm som enbart använder regressionsstatistik och modellerande av statistiska parametrar utvecklades. Denna algoritm levererade jämförbara resultat med föregående algoritm men gav även kraftigt förbättrad effektivitet.

The aim of this thesis was studying and describing known methods for testing transmission parameters in data networks based on protocol stack TCP/IP. Firstly were individual transmission parameters specified and determined their impact on service quality. Another aim was to carry out a comparison of the different methodologies of measurement of transmission parameters, performed their qualifications on the basis of these findings and methodology for measuring service quality from the user's perspective was proposed. It was a web application where users measured basic transmission parameters, then the users judged videos according to the evaluation scale MOS (Mean Opinion Score) and with the help of these data was analysis, classification connection and impact of connection on MOS evaluation.

Scaling has been pivotal in the success of the Moore's law. Using scaling techniques to improve the MOSFET comes at a risk of growing short channel effects. This publication deals with the theoretical study of impact of gate length scaling on planar bulk MOSFET. A systematical study shows that the impact of short channel effects like drain induced barrier lowering, subthreshold leakage, hot carrier generation and channel length modulation grows with gate length scaling. Thereby degrading the MOSFET performance. In addition to the numerical device simulation an analytical modelling of the device is also performed. Though the analytical model explains the device characteristic trends, it is found to be quantitative inaccurate in comparison to the numerical model especially when scaling below deep sub-micrometer regime.

Streaming 360° video has become more commonplace with content delivery services such as YouTube having support for it. By its nature, 360° video requires more bandwidth as only a fraction of the image is actually in view, while the user is expecting the same "in view" quality as with a regular video. Several studies and lots of work have been done to mitigate this higher demand for bandwidth. One solution is advanced algorithms that take in to account the direction that the user is looking when fetching the video from the server; e.g., by fetching content that is not in the user’s view at a lower quality or by not fetching this data at all. Developing these algorithms is a timely process, especially in the later stages where tweaking one parameter might require the video to be re-encoded, and therefore taking up time that could otherwise be spent on getting results and continued iteration on the algorithm. The viewer should also be considered as the best experience might not correlate with the mathematically best solution calculated by the algorithm. This thesis presents a modular emulator that allows for easy implementation of fetching algorithms that make use of state-of-the-art techniques. It intends to reduce the time it takes to iterate over an algorithm through removing the need to set up a server and encode the video in all of the wanted quality levels when a parameter change would require it. It also makes it easy to include the viewer in the process so that the subjective performance is taken into consideration. The emulator is evaluated through the implementation and evaluation of two algorithms, one serving as a baseline to the second one, which is based on an algorithm developed by another group of researchers. These algorithms are tested on two different types of 360° videos, under four different network conditions and with two values for the maximum buffer size. The results from the evaluation of the two algorithms suggest that the emulator functions as intended from a technical point of view, and as such fulfills its purpose. There is, however, future work that would further prove the emulators performance in regards to replicating real scenarios and a few examples are suggested.

Long-range communication proves to be a challenge due to the Earth’s curvature, since electromagnetic waves propagate away from the Earth’s surface in a free atmosphere. A possible solution to beyond line-of-sight communication is the atmospheric phenomenon known as the evaporation duct. Ducting occurs when the refractive index of the atmosphere rapidly decreases with height, which leads to ray trajectories bending inward towards the surface of the Earth, effectively creating a waveguide and enabling long-distance communication. In this work, the models by Paulus-Jeske and Babin-Young-Carton are investigated and implemented in MATLAB for calculation of the evaporation duct height and for modelling the refractive index of the atmosphere. The rapid decrease in refractive index giving rise to evaporation ducts occurs due to evaporation of water within the atmosphericsurface layer (<100 m over the surface), which is the domain of turbulent mixing in the atmosphere. With atmospheric data from a Weather API by Meteomatics, Monin-Obukhov similarity theory for the atmospheric surface layer is combined with a bulk flux parameterization scheme from the COARE experiment to determine the air-sea fluxes in the lower troposphere. The surface layer variables with stability functions from Businger-Dyer, Beljaars-Holtslag, Cheng-Brutsaert, and the SHEBA experiment are used in the evaporation duct models proposed by Paulus-Jeske and Babin-Young-Carton to calculate the evaporation duct height, finding that the latter is a valid method with Monin-Obukhov stability functions based on the SHEBA experiment. The modelled refractive index is inserted into an already existing wave propagation model to investigate and validate the findings. / Långdistanskommunikation är en utmaning på grund av jordens krökning, eftersom elektromagnetiska vågor sprider sig bort från jordens yta vid propagering i fri atmosfär. En möjlig lösning för kommunikation bortom siktlinjen är det atmosfäriska fenomenet som kallas avdunstningskanal. Det uppstår när atmosfärens brytningsindex snabbt minskar med höjden, vilket leder till att strålbanorna böjer sig inåt mot jordens yta, vilket i praktiken skapar en vågledare och möjliggör långdistanskommunikation. I detta arbete undersöks och implementeras modeller beskrivna av Paulus-Jeske och Babin-Young-Carton i MATLAB för beräkning av avdunstningskanalens höjd och för modellering av atmosfärens brytningsindex. Den snabba minskningen av brytningsindexet som ger upphov till avdunstningskanaler beror på avdunstning avvatten i det atmosfäriska ytskiktet (<100 m över ytan), som är det område där den turbulenta blandningen i atmosfären sker. Med atmosfäriska data från Weather API av Meteomatics kombineras Monin-Obukhovs likvärdighetsteori för det atmosfäriska ytskiktet med ett parametriseringsschema för bulkflöden från COARE-experimentet för att bestämma luft- och havsflödena i den nedre troposfären. Variablerna för ytskiktet med stabilitetsfunktioner från Businger-Dyer, Beljaars-Holtslag, Cheng-Brutsaert och SHEBA-experimentet används i de modeller för avdunstningskanaler som föreslagits av Paulus-Jeske och Babin-Young-Carton för att beräkna avdunstningskanalens höjd, varvid det konstateras att den sistnämnda metoden är en giltig metod med Monin-Obukhovs stabilitetsfunktioner baserade på SHEBA-experimentet. Det modellerade brytningsindexet införs i en redan befintlig vågutbredningsmodell för att undersöka och validera resultaten.