Orientadores: Edson Moschim, Felipe Rudge Barbosa / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação / Made available in DSpace on 2018-08-07T06:09:06Z (GMT). No. of bitstreams: 1 Nascimento_LuizHenriqueBonanido_D.pdf: 2297657 bytes, checksum: b04918af9ef98f4cae4bd6c3d6d4c0ca (MD5) Previous issue date: 2006 / Resumo: Hoje em dia, como uma multiplicidade muito grande de tecnologias converge para as redes fotônicas, a demanda por vazão cresce. Os protocolos para acesso múltiplo e simultâneo às portas de entrada da rede, bem como a abordagem do formato dos pacotes fotônicos e a arquitetura das redes, são considerados como alternativas tecnológicas para a melhora do desempenho das redes fotônicas. Deste modo, apresenta-se aqui uma proposta para a arquitetura de redes fotônicas,utilizando topologias em malha otimizadas para que os pacotes atinjam seus respectivos nós de destino no menor número de hops possível, com nós de rede 2x2. Além disso, utiliza-se o roteamento por deflexão para a resolução de contenda entre pacotes ópticos, bem como buffers eletrônicos na entrada da rede óptica para evitar problemas de perdas de inserção. Além disso, a estrutura de rede permite hierarquização e também se propõe um modelo para o funcionamento do nó que faz a ligação entre hierarquias diferentes dentro da rede óptica. Esta arquitetura de rede é então avaliada quanto à sua capacidade de prover requisitos para QoS em termos de perdas de pacotes, atrasos e inversão de ordem de pacotes, para a qual é proposta uma heurística para uma avaliação quantitativa. Os resultados mostram que uma arquitetura nos moldes apresentados é capaz de prover ganhos de desempenho, oferecendo condições para a garantia de QoS, provida por protocolos de rede em nível superior, até cerca de 70% de carga / Abstract: Nowadays, as a multiplicity of technologies converges upon the optical network, the demand for throughput increases. The protocols for multiple and simultaneous access to network ports, as well as the optical packet approach should be considered as technological alternatives to optical network performance upgrade. Thus, we present here a new proposal to the architecture of optical packet networks, using mesh topologies optimized in such a way that the packets reach their respective destination nodes with the smaller possible number of hops, and using 2x2 network nodes. Besides, we use deflection routing to solve the contention between optical packets, as well as electronical buffers at the optical network input to prevent problems with insertion losses. The structure of the network also allows hierarchization, performing the link between different hierarchies on the optical network. The performance of the proposed architecture is evaluated by the capacity of providing requirements of QoS, in terms of packet losses, delays and the amount of out of order packets, for which is presented a heuristic to get a quantitative estimation. The results show that the proposed architecture is able to provide performance gains, giving conditions to guarantee some levels of QoS, which is done by the specific protocols of superior network layers, up to 70% of network load / Doutorado / Telecomunicações e Telemática / Doutor em Engenharia Elétrica

Orientador: João Virgilio Merighi / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo / Made available in DSpace on 2018-08-14T08:55:45Z (GMT). No. of bitstreams: 1 Luis_AndreDenis_M.pdf: 9014700 bytes, checksum: b97f4cb26221bdd835d39342c297c2b8 (MD5) Previous issue date: 2009 / Resumo: Esta pesquisa versa sobre a utilização do equipamento FWD - Falling Weight Deflectometer, sendo analisados os diversos aspectos que influenciam nos resultados dos ensaios com o equipamento FWD. Dificuldade de interpretações das especificidades de tipos distintos de estruturas de pavimentos e uma vasta gama de correlações com a Viga Benkelman, as quais foram deduzidas por autores de diversas nacionalidades, demonstram que não há regra harmônica para os estudos. Assim, faz se imprescindível a percepção acurada, a consciência e experiência adquirida do engenheiro de projeto em cada situação. Esta hipótese foi corroborada pelo estudo dos ensaios realizados em malha viária experimental, abordados nesta dissertação. São propostos ainda temas relevantes para futuro desenvolvimento que possam agregar em confiabilidade e em economia dos projetos de pavimentação na Engenharia Nacional. Este trabalho foi desenvolvido utilizando-se a bibliografia sobre deflectometria internacional e brasileira, abrangendo os editais de concessões rodoviárias estaduais e federais. / Abstract: This research is about the use of equipment FWO - Falling Weight Deflectometer, and analyzed the various aspects that influence the results of tests with the FWO equipment. Difficulty in interpretation of the peculiarities of different types of pavement structures and a wide range of correlations with the Benkelman beam, which were derived by authors from different nationalities, shows that there is no rule for harmonic studies. Thus, it is essential to accurate perception, awareness and experience of the design engineer in every situation. This hypothesis was confirmed by the study of tests on experimental road network, discussed in this dissertation. Are still relevant topics proposed for future development that can add reliability and economy of paving projects in the National Engineering. This work was developed using the literature on international and Brazilian deflection, covering the tenders for state andfederal road concessions. / Mestrado / Transportes / Mestre em Engenharia Civil

As obras de infraestrutura rodoviária representam investimentos públicos que influenciam de maneira determinante no desenvolvimento social e econômico de uma região. Pavimentos mal construídos, com controle de qualidade inadequado ou que não atendam às exigências de projeto em termos de características e espessuras dos materiais selecionados representam prejuízos sociais e econômicos na medida em que a deterioração precoce do pavimento implica em aumentos crescentes nos custos diretos e indiretos relacionados à conservação e operação rodoviária. Desta maneira, torna-se imprescindível que sejam adotadas medidas de garantia da qualidade da construção de modo que o investimento apresente melhores condições de atingir o retorno esperado, tal como planejado. Neste contexto, o presente trabalho tem por objetivo realizar revisão bibliográfica e propor ferramentas auxiliares de análise voltados ao controle deflectométrico do sistema de fundação dos pavimentos. Os estudos realizados baseiam-se em critérios estatísticos de análise e em critérios de ruptura adotados nos métodos de dimensionamento em uso corrente no Brasil e no exterior. Simulações e estudos de casos são utilizados na validação e apresentação dos modelos propostos. / The infrastructure road projects represent investments, often public, that influence in a decisive way on social and economic development of a region. Poorly constructed pavements with inadequate quality control or that do not meet design requirements in terms of selected materials characteristics and thickness represent social and economic losses since the early deterioration of the pavement results in incremental increases in direct and indirect costs related the road maintenance and operation. Thus, it is essential that actions be taken to guarantee the construction quality so that investments are more likely to achieve the expected return as planned. In this context, this research aims to conduct a literature review and propose auxiliary analysis tools related with nondestructive deflection tests in the pavements foundation systems. The studies will be based in statistical analysis criteria and failure criteria adopted in design methods currently in use in Brazil and abroad. Simulations and study cases are used in the validation and presentation of the proposed models.

Neste trabalho são estudados dois problemas, como resumidos abaixo: Parte I - Deflexão Solar do Gráviton Neste trabalho calculamos o ângulo de deflexão do gráviton pelo Sol através de sua seção de choque diferencial de espalhamento. A expressão para a seção de choque é obtida através de uma teoria semi-clássica. O resultado obtido para o ângulo de desvio do gráviton, para pequenos ângulos, é o mesmo atribuído à luz, na sua geodésica nula. O conteúdo deste trabalho deu origem ao artigo: Ragusa, S. and Céleri, L. C., Gen. Relativ.. Solar Grauitational Deflection of a Graviton. 35, 1125 (2003). Parte II - Energia Gravitacional em uma Teoria Não-Simétrica da Gravitação A ausência de modos radiativos de energia negativa numa proposta teoria da gravitação baseada em uma métrica não-simétrica é reanalizada. Isto porque a contribuição de uma parte da lagrangeana deixou de ser considerada. Mostramos aqui que tal contribuição para a energia é nula. O caráter de positividade da energia na teoria fica então firmemente estabelecido. O conteúdo deste trabalho deu origem ao trabalho: Ragusa, S. and Céleri, L. C. Ghost-free Analysis of a Nonsymmetric Theory of Gravitation. Aceito para publicação no Brazilian Journal of Physics. / In this work two problems are studied, as summarized below: Part I - Deflection of the Solar Gráviton. This work calculated the deflection angle of the sun through the graviton your section of the shock of differential scattering. The term for the section of shock is obtained through a semi-classical theory. The result obtained for the angle of deflection of graviton for small angles, it is assigned to light, in its null geodesic. The content of this work led to the article: Ragusa, S. and rapid, L. C., Gen. Relative.. Solar Gravitational Deflection of the Graviton. 35, 1125 (2003). Part II - Energy in a Gravitational Theory of Non-Symmetric Gravitation. The absence of radiation modes of negative energy in a proposed theory of gravitation based on a non-symmetric metric is re-analyzed. This is because the contribution of part of lagrangean no longer be considered. We here show that this contribution to the energy is zero. The positive character of the energy in the theory is then firmly established. The content of this work led to the work: Ragusa, S. and rapid, L. C. Ghost-free Analysis of the Nonsymmetric Theory of Gravitation. Accepted for publication in Brazilian Journal of Physics.

[pt] Nesta dissertação são estudados a flambagem e o comportamento pós-crítico de colunas esbeltas sob a ação do peso próprio. Primeiramente, é realizada uma análise linear para a determinação das cargas críticas e modos críticos para colunas com diferentes condições de contorno e para a determinação da relação carga-frequência. Para estudar o comportamento pós-crítico da coluna, uma formulação geometricamente exata para a análise não-linear de elementos estruturais unidimensionais foi desenvolvida, considerando uma distribuição arbitrária da carga e condições de contorno. A partir desta formulação obtém-se um conjunto de equações não-lineares de primeira ordem, as quais,juntamente com as condições de contorno dos extremos da coluna, formam o problema de valor de contorno. Este problema é resolvido pelo uso simultâneo do método de integração numérica de Runge-Kutta e pelo método de Newton- Raphson. Devido a um algorítmo de continuação, soluções precisas podem ser obtidas para uma variedade de problemas de estabilidade apresentando pontos limite ou de bifurcação. Com o uso desta formulação, é feita uma análise paramétrica detalhada a fim de possibilitar o estudo da flambagem e do comportamento pós-crítico de colunas esbeltas sujeitas a ação do peso próprio, incluindo a influência das condições de contorno na estabilidade, a distribuição dos esforços internos e o comportamento não- linear geométrico da coluna. Com o objetivo de verificar a qualidade e a precisão dos resultados, foi conduzida uma análise experimental para o caso de uma coluna esbelta engastada e livre. Os resultados experimentais obtidos para a flambagem, freqüências naturais e para o comportamento pós-crítico foram comparados de forma favorável com os resultados teóricos e numéricos. / [en] In this thesis the buckling and post-buckling behavior of slenders columns under self-weight are studied. First a linear analysis is conducted to determine the critical loads for different boundary conditions and the load-frequency relation. In order to study the post-buckling behavior of the column, a geometrically exact formulation for the non- linear analysis of uni-dimentional structural elements has been derived, considering arbitrary load distribution and boundary conditions. From this formulation one obtains a set of first-order coupled non-linear equations which, together with the boundary conditions at the column ends, form a two-point boundary value problem. This problem is solved by the simultaneous use of the Runge-Kutta integration scheme and the Newton-Raphson method. By virtue of a continuation algorithm, accurate solutions can be obtained for a variety of stability problems exhibiting either limit point or bifurcational-type buckling. Using this formulation, a detailed parametric analysis is conducted in order to study the buckling and post-buckling behavior of slender columns under self-weight, including the influence of boundary conditions on the stability, internal forces distribution and large deflection behavior of the column. To verify the quality and accuracy of the results, an experimental analysis was conducted considering a clamped-free thin-walled metal column. The buckling and post-buckling behavior as well as the load-frequency relation were obtained and compared favorably with the theoretical and numerical results. / [es] En esta disertación se estudian el flameo el comportamiento postcrítico de columnas esbeltas bajo la acción del peso proprio. Primeramente, se realiza un análisis lineal para la determinación de las cargas críticas y modos críticos para columnas con diferentes condiciones de contorno y para la determinación de la relación carga frecuencia. Para estudiar el comportamiento postcrítico de la columna, fue desarrollada una formulación geométricamente exacta para el análisis no lineal de elementos extructurales unidimensionales, considerando una distribuición arbitraria de la carga y condiciones de contorno. A partir de esta formulación se obtiene un conjunto de ecuaciones no lineales de primer orden, las cuales, juntamente con las condiciones de contorno de los extremos de la columna, forman el problema de valor de contorno. Este problema se resuelve usando simultáneamente el método de integración numérica de Runge Kutta y el método de Newton Raphson. A través de un algorítmo de continuación, pueden ser obtenidas soluciones precisas para una variedad de problemas de estabilidad presentando puntos límite o de bifurcación. Utilizando esta formulación, se realiza análisis paramétrico detallado a fin de hacer posible el estudio del flameo y del comportamiento postcrítico de columnas esbeltas sujetas a la acción del proprio peso, inclyendo la influencia de las condiciones de contorno en la estabilidad, la distribuición de los esfuerzos internos y el comportamiento no lineal geométrico de la columna. Con el objetivo de verificar la calidad y la precisión de los resultados, se ejecutó un análisis experimental para el caso de una columna esbelta y libre. Los resultados experimentales obtenidos para el flameo, frecuencias naturales y para el comportamiento postcrítico fueron comparados de forma favorable con los resultados teóricos y numéricos.

Structural health monitoring systems have a great potential for cost saving and safety improvement in different types of structures. One of the most important tasks of these systems is to identify damage at an early stage of its development. A variety of methods may be used to identify, locate, or quantify the extent of damage or fault in a structural or mechanical component. However, the preferable method is the one which maximises the probability of detecting the flaw, while also considering feasibility of in-situ testing, ease of use and economic factors. Cracks are one of the common defects in structural components that may ultimately lead to failure of structures if not detected. The presence of cracks in a structure brings about local variations in the stiffness of the structure. These variations cause the dynamic behaviour of the cracked structure to be different from that of a healthy one. Vibration-based damage detection methods have attracted considerable attention over the past few decades. These methods generally use changes to the physical properties of structures for the purpose of crack detection. In this thesis, two new vibration-based methods have been developed for damage detection in beam-like and rotor-type structures. The first method performs the entire signal processing required for crack detection in time domain. It is based on assessing the normality of vibration responses using the normal probability plot (NPP). The amount of deviation between the actual and normal distribution of measured vibration responses was calculated along the length of the structure to localise the crack. The second proposed method converts the vibration responses into frequency domain for further processing. Excitation of the cracked structure at a given frequency always generates higher harmonic components of the exciting frequency due to the breathing of the crack. This method uses the operational deflection shape of the structure at the exciting frequency and its higher harmonics to identify the crack location. Avoiding complicated signal processing in frequency domain is the main advantage of the first method. However, more precise identification of crack locations can be obtained through the second method. Generally, both methods have the advantage of being easy, reference-free and applicable to in-situ testing for any structure. The concept and computational approach of both methods along with their validations through numerical and experimental examples have been presented. Moreover, different input excitations have been used to evaluate the capability of the developed methods in detecting the crack location(s).

No description available.

According to the US Department of Transportation, around 20 people die on a daily basis in a signalized intersection, with most of these resulting from angle or head-on collisions. The US-DoT’s Federal Highway Administration (FHWA) has identified modern roundabout intersections to be substantially safer than signalized intersections, due in part to the reduction in conflict points from 32 in a traditional signalized intersection to 8 in a modern roundabout. Despite the increased adoption of modern roundabouts across the US, there are a number of specific design elements for which the direct impact they have on operational and safety related performance of the roundabout remains unknown. To be specific, there is currently no conclusive research on the direct effects related to the introduction of a reverse curve (S-curve) on the approach to a roundabout. Moreover, what are the impacts of S-curves of varying geometries on the approach to a roundabout? This research employed a series of microsimulation-based analyses to investigate the speed related impacts related to the introduction to S-curves on the entry to a roundabout. An existing roundabout, in Amherst, MA, USA was used as a case study for this experiment. The data at each approach of the roundabout was collected by a static camera strategically placed to attain both the pedestrian and vehicle count during peak traffic hours. The data was manually reviewed to determine the upstream and downstream vehicle counts. The dimensions and angles of the existing roundabout were measured from Google earth and the image was extracted to AutoCaD Civil 3D. Since the objective is to check whether S-curves near an approach have a significant impact in speed, the deflection angle of the roundabout was not altered. The turning radius and angle at the approach was cross verified by measuring it on site. The existing roundabout was considered as the base model. The four approaches of the roundabout have different entry angles and radii. The revised models were drafted by strategically placing the S-curve at each approach and by steadily increasing their deflection angle and approach radius. The base and revised models cases were initially modelled, after which the conventional linear approach was modified to an S-curve and evaluated. Field data from the locations were to and calibrate microsimulation models on AIMSUN. The resulting trajectory data was analyzed for both the base case as well as three levels of experimental S-curves (ranging from 30 to 60 degrees) on each roundabout approach (16 total). The results provide evidence to suggest that a significant reduction in speed can be realized with a minimal amount of the reverse curvature on the roundabout approach. The trajectory output files were then imported into the Surrogate Safety Assessment Model (SSAM) to determine the number and type of conflicts experienced at each approach under each scenario evaluated in AIMSUN.

Human knee kinematics, especially during gait, are an important analysis tool. The current "gold standard" for kinematics measurement is a multi-camera, marker-based motion capture system with 3D position tracking. These systems are accurate but expensive and their use is limited to a confined laboratory environment. High deflection strain gauges (HDSG) are a novel class of sensors that have the potential to measure kinematics and can be inexpensive, low profile, and are not limited to measurements within a calibrated volume. However, many HDSG sensors can have a non-linear and non-monotonic response. This thesis explores using a nanocomposite HDSG sensor system for measuring knee kinematics in walking gait and overcoming the non-monotonic sensor response found in HDSGs through advanced modeling techniques. Nanocomposite HDSG sensors were placed across the knee joint in nine subjects during walking gait at three speeds and three inclines. The piezoresistive response of the sensors was obtained by including the sensors in a simple electrical circuit and recorded using a low-cost microcontroller. The voltage response from the system was used in four models. The first two models included a physics-based log-normal model and statistical functional data analysis model that estimated continuous knee angles. The third model was a discrete linear regression model that estimated the inflection points on the knee flexion/extension cycle. Finally, a machine learning approach helped to predict subject speed and incline of the walking surface. The models showed the sensor has the capability to provide knee kinematic data to a degree of accuracy comparable to similar kinematic sensors. The log-normal model had a 0.45 r-squared and was unsuitable as a stand-alone continuous angle predictor. After running a 10-fold cross validation the functional data analysis (FDA) model had an overall RMSE of 3.4° and could be used to predict the entire knee flexion/extension angle cycle. The discrete linear regression model predicted the inflection points on the knee kinematics graph during each gait cycle with an average RMSE of 1.92° for angle measures and 0.0332 seconds for time measures. In every estimate, the discrete linear regression model performed better than the FDA model at those points. The 10-fold cross validation of the machine learning approach using the discrete voltages could predict the categorical incline 90% of the time and the RMSE for the speed model was 0.23 MPH. The use of a HDSG as a knee kinematics sensor was shown as a viable alternative to existing motion capture technology. In future work, it is recommended that a calibration method be developed that would allow this sensor to be used independent of a motion capture system. With these advancements, this inexpensive and low profile HDSG will advance understanding of human gait and kinematics in a more affordable and scope enhancing way.

This thesis deals with use of the measuring system MAAS-1 for direct determination of vertical deviations at the points specified field. The main input data are geographical and astronomical coordinates of points. The aim of this thesis is to complete the processing of data measured in the locality.