938 resultados para Full wave analysis


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The accurate and reliable estimation of travel time based on point detector data is needed to support Intelligent Transportation System (ITS) applications. It has been found that the quality of travel time estimation is a function of the method used in the estimation and varies for different traffic conditions. In this study, two hybrid on-line travel time estimation models, and their corresponding off-line methods, were developed to achieve better estimation performance under various traffic conditions, including recurrent congestion and incidents. The first model combines the Mid-Point method, which is a speed-based method, with a traffic flow-based method. The second model integrates two speed-based methods: the Mid-Point method and the Minimum Speed method. In both models, the switch between travel time estimation methods is based on the congestion level and queue status automatically identified by clustering analysis. During incident conditions with rapidly changing queue lengths, shock wave analysis-based refinements are applied for on-line estimation to capture the fast queue propagation and recovery. Travel time estimates obtained from existing speed-based methods, traffic flow-based methods, and the models developed were tested using both simulation and real-world data. The results indicate that all tested methods performed at an acceptable level during periods of low congestion. However, their performances vary with an increase in congestion. Comparisons with other estimation methods also show that the developed hybrid models perform well in all cases. Further comparisons between the on-line and off-line travel time estimation methods reveal that off-line methods perform significantly better only during fast-changing congested conditions, such as during incidents. The impacts of major influential factors on the performance of travel time estimation, including data preprocessing procedures, detector errors, detector spacing, frequency of travel time updates to traveler information devices, travel time link length, and posted travel time range, were investigated in this study. The results show that these factors have more significant impacts on the estimation accuracy and reliability under congested conditions than during uncongested conditions. For the incident conditions, the estimation quality improves with the use of a short rolling period for data smoothing, more accurate detector data, and frequent travel time updates.

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There is growing popularity in the use of composite indices and rankings for cross-organizational benchmarking. However, little attention has been paid to alternative methods and procedures for the computation of these indices and how the use of such methods may impact the resulting indices and rankings. This dissertation developed an approach for assessing composite indices and rankings based on the integration of a number of methods for aggregation, data transformation and attribute weighting involved in their computation. The integrated model developed is based on the simulation of composite indices using methods and procedures proposed in the area of multi-criteria decision making (MCDM) and knowledge discovery in databases (KDD). The approach developed in this dissertation was automated through an IT artifact that was designed, developed and evaluated based on the framework and guidelines of the design science paradigm of information systems research. This artifact dynamically generates multiple versions of indices and rankings by considering different methodological scenarios according to user specified parameters. The computerized implementation was done in Visual Basic for Excel 2007. Using different performance measures, the artifact produces a number of excel outputs for the comparison and assessment of the indices and rankings. In order to evaluate the efficacy of the artifact and its underlying approach, a full empirical analysis was conducted using the World Bank's Doing Business database for the year 2010, which includes ten sub-indices (each corresponding to different areas of the business environment and regulation) for 183 countries. The output results, which were obtained using 115 methodological scenarios for the assessment of this index and its ten sub-indices, indicated that the variability of the component indicators considered in each case influenced the sensitivity of the rankings to the methodological choices. Overall, the results of our multi-method assessment were consistent with the World Bank rankings except in cases where the indices involved cost indicators measured in per capita income which yielded more sensitive results. Low income level countries exhibited more sensitivity in their rankings and less agreement between the benchmark rankings and our multi-method based rankings than higher income country groups.

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The past years have seen a great interest in the use of frequency selective surfaces (FSS), as spatial filters, in many microwave applications. Among these, we highlight applications in telecommunication systems (such as satellite communications and radar), high gain antennas (combined with planar antennas) and (home and industrial) microwave ovens. The FSS is usually composed of two-dimensional periodic arrays, with equally spaced elements, which may be metallic patches (printed on dielectric substrates) or aperture (holes in thin metal surfaces). Using periodic arrays, the FSS have been able to meet the demands of the telecommunications industry. However, new demands are finding technological limitations. In this context, adverse filtering requirements have forced designers to use FSS optimization methods to find specific formats of FSS elements. Another alternative that has been used to increase the selectivity of the FSS is the cascaded FSS, a simple technique that has as main drawback the increased dimensions of the structure, as well as its weight. This work proposes the development of a new class of selective surfaces frequency (FSS) composed of quasi-periodic (or non-periodic) arrangements. The proposed FSS have no array periodicity, in relation with the spatial position of their elements. The frequency responses of these structures were simulated using commercial softwares that implement full-wave methods. For the purpose of validation of this study, FSS prototypes were built and measured, being possible to observe a good agreement between simulated and measured results. The main conclusions of this work are presented, as well as suggestions for future works.

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It is shown that the direction-of-arrival (DoA) information carried by an incident electromagnetic (EM) wave can be encoded into the evanescent near field of an electrically small resonance antenna array with a spatial rate higher than that of the incident field oscillation rate in free space. Phase conjugation of the received signal leads to the retrodirection of the near field in the antenna array environment, which in turn generates a retrodirected far-field beam toward the original DoA. This EM phenomenon enables electrically small retrodirective antenna arrays with superdirective, angular super-resolution, auto-pointing properties for an arbitrary DoA. A theoretical explanation of the phenomenon based on first principal observations is given and full-wave simulations demonstrate a realizability route for the proposed retrodirective terminal that is comprised of resonance dipole antenna elements. Specifically, it is shown that a three-element disk-loaded retrodirective dipole array with 0.15\lambda spacings can achieve a 3.4-dBi maximal gain, 3-dBi front-to-back ratio, and 13% return loss fractional bandwidth (at the 10-dB level). Then, it is demonstrated that the radiation gain of a three-element array can be improved to approximately 6 dBi at the expense of the return loss fractional bandwidth reduction (2%).

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Understanding the overall catalytic activity trend for rational catalyst design is one of the core goals in heterogeneous catalysis. In the past two decades, the development of density functional theory (DFT) and surface kinetics make it feasible to theoretically evaluate and predict the catalytic activity variation of catalysts within a descriptor-based framework. Thereinto, the concept of the volcano curve, which reveals the general activity trend, usually constitutes the basic foundation of catalyst screening. However, although it is a widely accepted concept in heterogeneous catalysis, its origin lacks a clear physical picture and definite interpretation. Herein, starting with a brief review of the development of the catalyst screening framework, we use a two-step kinetic model to refine and clarify the origin of the volcano curve with a full analytical analysis by integrating the surface kinetics and the results of first-principles calculations. It is mathematically demonstrated that the volcano curve is an essential property in catalysis, which results from the self-poisoning effect accompanying the catalytic adsorption process. Specifically, when adsorption is strong, it is the rapid decrease of surface free sites rather than the augmentation of energy barriers that inhibits the overall reaction rate and results in the volcano curve. Some interesting points and implications in assisting catalyst screening are also discussed based on the kinetic derivation. Moreover, recent applications of the volcano curve for catalyst design in two important photoelectrocatalytic processes (the hydrogen evolution reaction and dye-sensitized solar cells) are also briefly discussed.

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The issue of this thesis concerns a selection of historical debates in which new Swedish drama is under discussion. The studied debates take place in the cultural and political fields and within the fields of theater and literature and deal with a recurring assumption in Swedish theatre history – that new Swedish drama is insufficient. The primary object of this thesis is to find explanations to: why is the Swedish new drama so often described as defective? The following questions, guiding the analysis, are: How are the crises described? What are the stakes? How has the dramatic text been influenced by being judged either as literary product or a product for the stage? How is the playwright’s role described, and perhaps changed, in the crises? The aim of the analysis is to understand how traditions and conventions are shaping the debates and contribute to perpetrate the myth of the malfunctioning Swedish new play. In a historical perspective several attempts have been made to govern new Swedish drama by legislative and political power. New Swedish drama has, for example, been viewed as a possible expression of the nation, as part of shaping the Swedish Welfare state or creating interactive communication with the audience. Despite its many uses, new Swedish drama continues to be describes as flawed. The study starts with King Gustav III:s Swedish theatre where the purpose was to produce Swedish original plays. The study ends with an analysis of a new government grant for new Swedish drama, which was installed in 1999. The chosen debates are analyzed with the help of concepts borrowed from the French sociologist Pierre Bourdieu, looking at each historical situation as a possible moment for the establishment of the field ”new Swedish drama”. The survey ends with eight interviews with playwrights, who are active today. The conditions for the new Swedish drama are the guiding line in this thesis. These conditions are found in the cultural, social and historical contexts that cooperate when a taste or convention is being shaped. They are part of the discourses in the field, where criteria for the new Swedish drama is formulated. In order to understand the significance of, for example, the expression, ”the newly written Swedish drama” research has been pursued in biographical material, historical surveys, and debates in the daily press and in professional journals. Without being a full bourdieuan analysis, the thesis is using concepts from Bourdieu. The work of British feminist theatre historian Tracy C Davis inspires the critical historic perspective.

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As anomalias dentárias podem ocorrer como resultado de fatores genéticos e ambientais. Estas são geralmente causadas por defeitos em genes específicos, no entanto, eventos pré e pós-natais têm também sido implicados em diferentes tipos de anomalias dentárias. Quando comparados com a população geral, os indivíduos que apresentam fenda labial (FL) e fenda palatina (FP) demonstraram ter uma maior prevalência de anomalias dentárias, tais como variações de número, posição e tamanho, que na sua maioria se localizavam na área do defeito da fenda. Com este trabalho, pretendeu-se então, realizar uma revisão narrativa sobre as várias anomalias dentárias que podem estar associadas a FL ou FP, a sua prevalência e as opções terapêuticas recomendadas. Durante os meses de Dezembro de 2012 e Janeiro de 2013 foi realizada uma pesquisa bibliográfica na base de dados Pubmed atendendo às seguintes palavras chave “dental anomalies” AND “cleft lip and palate”; “oral health” AND “cleft lip and palate”. Na pesquisa empregaram-se os seguintes limites, artigos publicados nos últimos cinco anos, estudos em humanos, abstract disponível e artigos disponíveis em português, inglês e espanhol. Nesta pesquisa obteve-se um total de 50 artigos. Os artigos encontrados foram seleccionados primeiramente pelo título, seguidamente pela leitura cuidadosa dos abstracts e, finalmente, do artigo por inteiro, daí resultando um total de 17 artigos. Para o melhor entendimento do tema a ser desenvolvido, foram ainda considerados artigos de referência publicados em anos anteriores e livros de Odontopediatria e Genética Orofacial. As crianças com FL ou FP apresentam maior prevalência de anomalias dentárias de forma, número, posição, erupção e estrutura dentária, com localização privilegiada na área do defeito da fenda. Os pacientes portadores desta malformação congénita necessitam de intervenção precoce e acompanhamento continuado ao longo de toda a infância e adolescência, por uma equipa multidisciplinar que deverá incluir o pediatra, cirurgião maxilofacial, médico dentista, terapeuta da fala, psicólogo e cirurgião plástico.

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O autismo é uma condição que faz parte de um grupo de perturbações do desenvolvimento global das funções cerebrais e que, por regra, é diagnosticada no início da infância. A dificuldade na linguagem e comunicação, o défice na interação social, as esteriotipias e os interesses específicos e comportamentos repetitivos caracterizam os indivíduos portadores desta patologia. A saúde oral das crianças autistas é geralmente precária e as necessidades de tratamento dentário elevadas. No entanto, os problemas comportamentais destes doentes fazem com que os pais não recorram às consultas de medicina dentária, outras vezes quando recorrem à consulta as dificuldades de colaboração impedem a prestação de cuidados de saúde oral adequados a estas crianças. Pretendeu-se assim, com este trabalho, realizar uma revisão sistemática de literatura científica, publicada nos últimos 15 anos, acerca dos problemas orais que atingem os pacientes autistas, e simultaneamente, compilar diretrizes de atuação clínica para orientar o médico dentista no atendimento destes doentes. Para isto, durante os meses de Outubro de 2014 a Outubro de 2015, procedeu-se a uma pesquisa bibliográfica nas bases de dados PubMed e B-on, sendo consultados também outros bancos de dados como LILACS – BIREME, SciELO, utilizando as seguintes palavras-chave: “autism”, “pediatric dentistry”, “Asperger Syndrome”, “Rett Syndrome”, “Childhood Disintegrative Disorder”, “prevalence”, “neurobiology”, “etiology”, “diagnosis”, “diagnostic criteria”, “comorbidity”, “oral health”, “dental caries”, “periodontal disease”, “oral habits”, “bruxism”, “self-injury”, “dental trauma”, “dental injury”, “malocclusion”, “behavior management techniques” separadas ou associadas pelo operador de pesquisa booleano AND. Na pesquisa foram empregues os seguintes limites: artigos publicados nos últimos 15 anos, abstract disponível, estudos em humanos e artigos e língua inglesa, francesa, portuguesa e espanhola. Desta pesquisa resultou um total de 150 artigos que foram selecionados primeiramente pelos títulos, seguidamente pela leitura dos abstracts e, finalmente, do artigo por inteiro, obtendo-se assim 95 artigos, para revisão. Foram ainda considerados artigos de referência publicados em anos anteriores, livros de texto médicos e publicações portuguesas com dados epidemiológicos sobre as Perturbações do Espetro do Autismo em Portugal. As doenças orais encontradas nas crianças autistas são semelhantes às das crianças sem qualquer perturbação mental, contudo a preferência por alimentos cariogénicos, a diminuição do fluxo salivar induzida pelos fármacos, associadas a uma pobre higiene oral, justificam uma maior prevalência de cárie. As doenças periodontais, também muito prevalentes neste grupo, desenvolvem-se em virtude da combinação da falta de hábitos de higiene oral, com os efeitos secundários de fármacos administrados a estes doentes, como os anticonvulsivantes. No seu atendimento na consulta dentária recorre-se às mesmas estratégias de orientação de comportamento aplicadas nas crianças saudáveis, para contornar os sentimentos de medo, ansiedade, desconfiança e a incapacidade de interação social, e assim evitar comportamentos de recusa durante a consulta dentária. É no entanto de salientar que os distúrbios comportamentais, o défice da comunicação e a falta de capacidades de interação social, caraterísticas do autismo impossibilitam a eficácia das técnicas de controlo do comportamento comunicativas, obrigando, muitas vezes, ao uso de técnicas de controlo de comportamento avançadas para prestação de cuidados de saúde oral com eficácia e em segurança. É importante uma grande motivação de pais/responsáveis para a saúde e higiene oral das crianças com Perturbações do Espetro do Autismo, e que todos os profissionais de saúde envolvidos no cuidado destes doentes contribuam para a aprendizagem de comportamentos que promovam a saúde oral destes doentes.

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In April 2017, CMEMS plans to launch the WAVES NRT products. This document is focused in the automatic RTQC of the collected wave data. The validation procedure includes the delayed mode quality control of the data and will be specified in another guideline. To perform any kind of quality control to wave data, first it’s necessary to know the nature of the measurements and the analysis performed to those measurements to obtain the wave parameters. For that reason next chapter is dedicated to show the usual wave analysis and the different parameters and estimators obtained.

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El objetivo del presente estudio fue cuantificar la contribución del sobrepeso en la magnitud de la lipemia posprandial en sujetos normolipídicos. Se incluyeron 33 adultos normolipídicos en dos grupos (n=20, sobrepeso y (n=13 eutróficos, 66% hombres, edad media 31,2±7,6 años). Se midió la vasodilatación mediada por flujo (VMF), la velocidad de onda de pulso (VOP), el perfil lipídico, el cociente Log TG/c-HDL, la glucosa y presión arterial tras una ingesta estándar con alto contenido de grasa (79% Kcal/grasa). Se calculó, el Z-score de riesgo cardiovascular a partir de la suma de los residuos tipificados (Z) de las variables de riesgo cardiovascular. El estado de lipemia posprandial se midió en ayuno (0 min) y a los (60, 120, 180, y 240 min) posprandiales. El valor basal de la VMF y la VOP fue de 6,9±5,9% y 7.0±0.8 m/s, respectivamente. Se identificó que la lipemia posprandial reducía la WMF en 19,2% a los 60 min (5,9±1,5%) y a los 240 min (3,7±1,2%) (p<0,04), respectivamente. Este hallazgo se acompañó con un aumento en la VOP (p<0,05). Al dividir los sujetos en dos grupos según el IMC, los participantes en sobrepeso muestran cifras más elevadas en el Z-score de riesgo cardiovascular, la VOP, el Log TG/c-HDL y el Δ-VOP, (p<0,001). En conclusión los sujetos clasificados en sobrepeso muestran un perfil cardiometabolico asociado con un mayor riesgo cardiovascular.

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The presented Thesis describes the design of RF-energy harvesting systems with applications on different environments, from the biomedical side to the industrial one, tackling the common thread problem which is the design of complete energy autonomous tags each of them with its dedicated purpose. This Thesis gathers a work of three years in the field of energy harvesting system design, a combination of full-wave electromagnetic designs to optimize not only the antenna performance but also to fulfill the requirements given by each case study such as dimensions, insensitivity from the surrounding environment, flexibility and compliance with regulations. The research activity has been based on the development of highly-demanded ideas and real-case necessities which are in line with the environment in which modern IoT applications can really make a positive contribution. The Thesis is organized as follows: the first application, described in Chapter 2, regards the design and experimental validations of a rotation-insensitive WPT system for implantable devices. Chapter 3 presents the design of a wearable energy autonomous detector to identify the presence of ethanol on the body surface. Chapter 4 describes investigations in the use of Bessel Beam launchers for creating a highly-focused energy harvesting link for wearable applications. Reduced dimensions, high focusing and decoupling from the human body are the key points to be addressed during the full-wave design and nonlinear optimization of the receiver antenna. Finally, Chapter 5 presents an energy autonomous system exploiting LoRa (Long Range) nodes for tracking trailers in industrial plants. The novelty behind this design lies on the aim of obtaining a perfectly scalable system that exploits not only EH basic operating system but embeds a seamless solution for collecting a certain amount of power that varies with respect the received power level on the antenna, without the need of additional off-the-shelf components.

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Lhasa Apso dogs with immature, mature or hypermature cataracts were divided into four groups according to their age (G1: 1 to 3 years old, G2: 4 to 7 years old, G3: 8 to 11 years old, G4: more than 12 years old). All animals were evaluated under the same sedation protocol to allow the performance of the electroretinogram (ERG) exam to determine normal value of b-wave response of the full-field ERG according to age. Three ERG responses were recorded: rod, maximal and cone responses. The amplitude values and b-wave implicit time of the responses of all groups were compared and analyzed by Kruskal-Wallis test (variance analysis for non-repeated measures), followed by the Dunn post-test (when p<0,05). A significant decrease was observed in maximal responses' amplitude, when comparing the G4 group with G1 and G2. No statistically relevant differences were observed in the b-wave implicit time values between groups. The ERG values are directly influenced by the animal's age. Older patients presented a decrease in the amplitude of the maximal response. The study determined the normal parameters of ERG b-waves for Lhasa Apso dogs with cataract according to their age group.

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Wave solutions to a mechanochemical model for cytoskeletal activity are studied and the results applied to the waves of chemical and mechanical activity that sweep over an egg shortly after fertilization. The model takes into account the calcium-controlled presence of actively contractile units in the cytoplasm, and consists of a viscoelastic force equilibrium equation and a conservation equation for calcium. Using piecewise linear caricatures, we obtain analytic solutions for travelling waves on a strip and demonstrate uiat the full nonlinear system behaves as predicted by the analytic solutions. The equations are solved on a sphere and the numerical results are similar to the analytic solutions. We indicate how the speed of the waves can be used as a diagnostic tool with which the chemical reactivity of the egg surface can be measured.

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The full-scale base-isolated structure studied in this dissertation is the only base-isolated building in South Island of New Zealand. It sustained hundreds of earthquake ground motions from September 2010 and well into 2012. Several large earthquake responses were recorded in December 2011 by NEES@UCLA and by GeoNet recording station nearby Christchurch Women's Hospital. The primary focus of this dissertation is to advance the state-of-the art of the methods to evaluate performance of seismic-isolated structures and the effects of soil-structure interaction by developing new data processing methodologies to overcome current limitations and by implementing advanced numerical modeling in OpenSees for direct analysis of soil-structure interaction.

This dissertation presents a novel method for recovering force-displacement relations within the isolators of building structures with unknown nonlinearities from sparse seismic-response measurements of floor accelerations. The method requires only direct matrix calculations (factorizations and multiplications); no iterative trial-and-error methods are required. The method requires a mass matrix, or at least an estimate of the floor masses. A stiffness matrix may be used, but is not necessary. Essentially, the method operates on a matrix of incomplete measurements of floor accelerations. In the special case of complete floor measurements of systems with linear dynamics, real modes, and equal floor masses, the principal components of this matrix are the modal responses. In the more general case of partial measurements and nonlinear dynamics, the method extracts a number of linearly-dependent components from Hankel matrices of measured horizontal response accelerations, assembles these components row-wise and extracts principal components from the singular value decomposition of this large matrix of linearly-dependent components. These principal components are then interpolated between floors in a way that minimizes the curvature energy of the interpolation. This interpolation step can make use of a reduced-order stiffness matrix, a backward difference matrix or a central difference matrix. The measured and interpolated floor acceleration components at all floors are then assembled and multiplied by a mass matrix. The recovered in-service force-displacement relations are then incorporated into the OpenSees soil structure interaction model.

Numerical simulations of soil-structure interaction involving non-uniform soil behavior are conducted following the development of the complete soil-structure interaction model of Christchurch Women's Hospital in OpenSees. In these 2D OpenSees models, the superstructure is modeled as two-dimensional frames in short span and long span respectively. The lead rubber bearings are modeled as elastomeric bearing (Bouc Wen) elements. The soil underlying the concrete raft foundation is modeled with linear elastic plane strain quadrilateral element. The non-uniformity of the soil profile is incorporated by extraction and interpolation of shear wave velocity profile from the Canterbury Geotechnical Database. The validity of the complete two-dimensional soil-structure interaction OpenSees model for the hospital is checked by comparing the results of peak floor responses and force-displacement relations within the isolation system achieved from OpenSees simulations to the recorded measurements. General explanations and implications, supported by displacement drifts, floor acceleration and displacement responses, force-displacement relations are described to address the effects of soil-structure interaction.

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The wave energy industry is entering a new phase of pre-commercial and commercial deployments of full-scale devices, so better understanding of seaway variability is critical to the successful operation of devices. The response of Wave Energy Converters to incident waves govern their operational performance and for many devices, this is highly dependent on spectral shape due to their resonant properties. Various methods of wave measurement are presented, along with analysis techniques and empirical models. Resource assessments, device performance predictions and monitoring of operational devices will often be based on summary statistics and assume a standard spectral shape such as Pierson-Moskowitz or JONSWAP. Furthermore, these are typically derived from the closest available wave data, frequently separated from the site on scales in the order of 1km. Therefore, variability of seaways from standard spectral shapes and spatial inconsistency between the measurement point and the device site will cause inaccuracies in the performance assessment. This thesis categorises time and frequency domain analysis techniques that can be used to identify changes in a sea state from record to record. Device specific issues such as dimensional scaling of sea states and power output are discussed along with potential differences that arise in estimated and actual output power of a WEC due to spectral shape variation. This is investigated using measured data from various phases of device development.