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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
131

A influência de diferentes posturas da coluna cervical na análise do sinal de voz / The influence of different postures of cervical spine in the vocal signal analysis

Carneiro, Paula Rossi 09 August 2013 (has links)
A boa postura corporal é importante para otimizar a função vocal. Apesar de encontrado o assunto postura e voz na literatura, não foram encontradas pesquisas que estudem os posicionamentos específicos de cabeça e pescoço e como estas influenciam o sinal de voz. O objetivo do presente estudo foi verificar a influência da anteriorização, da posteriorização e da extensão da cabeça no sinal de voz. Foram selecionados 50 homens e 50 mulheres não tabagistas e sem queixas vocais, com idade média de 24,72 e 23,46 anos, respectivamente. Foram demarcados nos participantes três pontos anatômicos: acrômio da escápula, côndilo da mandíbula e processo xifoide do esterno. Os indivíduos foram fotografados sentados em vista lateral com a coluna vertebral ereta simultaneamente ao processo de gravação da vogal /a/ sustentada pelo programa Sound Forge 7.0® em quatro diferentes posturas cervicais: P1) ereta; P2) anteriorização de cabeça; P3) posteriorização de cabeça; e P4) extensão cervical. As posturas foram analisadas por fotogrametria computadorizada pelo programa Corel Draw X3®. As vozes foram estudadas por análise acústica por meio do programa MDVP e por avaliação perceptivo auditiva realizada por três fonoaudiólogos meio de uma escala visual analógica com 100 milímetros de comprimento. A partir dos pontos anatômicos demarcados foram estudados pela fotogrametria os ângulos: côndilo-acrômio (ACA), mento-esternal (AME) e de Frankfurt (AF). Os resultados posturais e vocais foram analisados estatisticamente pelos testes Anova e Tukey com p<0,05. Na fotogrametria, foram encontradas diferenças significantes (p<0,05) em ACA e AME na P2 e P3 em relação à P1 e em AF na P4 quando comparado à P1, para homens e mulheres. Na análise acústica da voz foram encontradas diferenças significantes (p<0,05) na frequência fundamental (F0) na comparação da P2 e P4 em relação à P1 em ambos os grupos, e no shimmer na P4 no grupo das mulheres. Na avaliação perceptivo auditiva foram encontradas diferenças significantes (p<0,05) na comparação da P2 com P1 com pior grau geral, maior tensão e pitch mais agudo para ambos os grupos e maior rugosidade no grupo dos homens na P2. Foi observado na comparação da P3 com P1 diferenças significativas (p<0,05) com pior grau geral, maior tensão, aumento do loudness, pitch mais agudo e maior rugosidade para ambos os grupos na P3. E na P4 foram encontradas pior grau geral, maior tensão, aumento do loudness e pitch mais agudo para ambos os grupos em relação à P1 (p<0,05), e maior rugosidade e soprosidade na P4 (p<0,05) para o grupo dos homens. Conclui-se que pelos achados fotogramétricos que os indivíduos se posicionaram corretamente nas posturas solicitadas. Nas posições da P2, P3 e P4 a voz se torna mais aguda, com maior tensão e com pior qualidade vocal quando comparadas à P1, e em P3 e P4 também se observa o aumento do loudness. / The good corporal posture is important to optimize the vocal function. Although the subject posture and voice has been found in the literature, it wasnt found researches that investigates how the specifics positions of head and neck influence the vocal signal. The aim of the present investigation was to verify the influence of forward head position, backward head position and cervical extension in the vocal signal. It was selected 50 men and 50 women, nonsmokers and without vocal complains, with average age of 24,72 and 23,46 years old, respectively. It was marked in the subjects three anatomic structures: acromion in the scapula, mandibular condyle and xiphoid process in the sternum. The participants were photographed sited in lateral view in a straight spine alignment simultaneously of the recording process of the sustained vowel /a/ by the program Sound Forge 7.0® in four different cervical postures: P1) straight alignment; P2) forward head position; P3) backward head position; and P4) cervical extension. The postures were analyzed by photogrammetry by the Corel Draw program. The voice were studied by acoustic analysis by the MDVP program and by perceptual speech analysis done by three speech therapists using a visual analogue scale with 100 millimeters of length. From the anatomic structures marked were studied by photogrammetry the angles: condyle-acromion (ACA), menton-sternum (AME) and Frankfurt (AF). The postural and vocal results were statistically analyzed by the Anova and Tukey tests with p<0,05. In the photogrammetry, were found significant differences (p<0,05) in ACA and AME in P2 and P3 in relation to P1 and in AF in P4 when compared to P1, for both men and women. IN the acoustic analysis were found significant differences (p<0,05) in fundamental frequency (F0) in the comparison of P2 and P4 with P1 in both groups, and in shimmer in the P4 for the women group. In the perceptual speech analysis were found significant differences (p<0,05) ) in the comparison of P2 with P1 with worse general degree, increased tension and pitch more acute for both groups and increased roughness for the men group in the P2. It was observed in the comparison of P3 with P1 significant differences (p<0,05) with worse general degree, increased tension, increased loudness, pitch more acute and increased roughness for both groups in P3. And in P4 were found worse general degree, increased tension, increased loudness and pitch more acute for both groups and increased roughness and breathiness in P4 (p<0,05) for the men group. It can be concluded by the founds in photogrammetry that the subjects were correctly positioned in the postures solicited. IN the P2, P3 and P4 positions the voice become more acute, with more tension and worse quality when compared to the P1 position, and also in P3 and P4 can be observed increased loudness.
132

Three-dimensional reconstruction of braided river morphology and morphodynamics with structure-from-motion photogrammetry

James, Joe Steven January 2018 (has links)
The recent emergence of Structure-from-Motion Photogrammetry (SfM) has created a cost-effective alternative to conventional laser scanning for the production of high-resolution topographic datasets. There has been an explosion of applications of SfM within the geomorphological community in recent years, however, the focus of these has largely been small-scale (102 - 103 m2), building on innovations in low altitude Unmanned Aircraft Systems (UAS). This thesis examines the potential to extend the scope of SfM photogrammetry in order to quantify of landscape scale processes. This is examined through repeat surveys of a ~35 km2 reach of the Dart River, New Zealand. An initial SfM survey of this reach was conducted in April 2014, following a large landslide at the Slipstream debris fan. Validation of the resulting digital elevation models using Independent Control Point's (ICPs) suggested encouraging results, however benchmarking the survey against a long-range laser scanned surface indicated the presence of significant systematic errors associated with inaccurate estimation of the SfM bundle adjustment. Using a combination of scaled laboratory field experiments, this research aimed to develop and test photogrammetric data collection and modelling strategies to enhance modelling of 3D scene structure using limited constraints. A repeat survey in 2015 provided an opportunity to evaluate a new survey strategy, incorporating a convergent camera network and a priori measurement of camera pose. This resulted in halving of mean checkpoint residuals and a reduction in systematic error. The models produced for both 2014 and 2015 were compared using a DEM differencing (DoD) methodology to assess the applicability of wide-area SfM models for the analysis of geomorphic change detection. The systematic errors within the 2014 model confound reliable change detection, although strategies to correlate the two surveys and measure the residual change show promise. The future use of SfM over broad landscape scales has significant potential, however, this will require robust data collection and modelling strategies and improved error modelling to increase user confidence.
133

Utilização da transformada de características invariante a escala (SIFT) na automatização da obtenção de pontos do Sistema de Imagens Tridimensional Híbrido (SITH) / Using the scale invariant feature transform (SIFT) in the automation of getting points of the three-dimensional hybrid imaging system (SITH)

Felipe Pereira do Carmo 23 July 2010 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Esta dissertação apresenta um aperfeiçoamento para o Sistema de Imagens Tridimensional Híbrido (SITH) que é utilizado para obtenção de uma superfície tridimensional do relevo de uma determinada região a partir de dois aerofotogramas consecutivos da mesma. A fotogrametria é a ciência e tecnologia utilizada para obter informações confiáveis a partir de imagens adquiridas por sensores. O aperfeiçoamento do SITH consistirá na automatização da obtenção dos pontos através da técnica de Transformada de Características Invariantes a Escala (SIFT - Scale Invariant Feature Transform) dos pares de imagens estereoscópicas obtidos por câmeras aéreas métricas, e na utilização de técnicas de interpolação por splines cúbicos para suavização das superfícies tridimensionais obtidas pelo mesmo, proporcionando uma visualização mais clara dos detalhes da área estudada e auxiliando em prevenções contra deslizamentos em locais de risco a partir de um planejamento urbano adequado. Os resultados computacionais mostram que a incorporação destes métodos ao programa SITH apresentaram bons resultados. / This dissertation presents an improvement of the Three-Dimensional Hybrid Imaging System (SITH) that is used to obtain a three dimensional surface relief of a particular region from the same two consecutive air frames it. Photogrammetry is the science and technology used to obtain reliable information from images acquired by sensors. Improving the automation of the SITH will consist of points obtained using the technique of Invariant Feature Transform Scale (SIFT - Scale Invariant Feature Transform) pair of stereoscopic images obtained by aerial metric cameras, and the use of means of cubic spline interpolation for smooth surfaces produced by the same three-dimensional, providing a clearer view of the details of the study area and aiding in effective prevention against landslides in hazardous locations from an urban planning appropriate. The computational results show that the incorporation of these methods to the program SITH had good results.
134

A Low-Cost Custom Knee Brace Via Smartphone Photogrammetry

Miguel, Olivier 25 January 2019 (has links)
This thesis provided the foundational work for a low-cost three-dimensional (3D) printed custom knee brace. Specifically, the objective was to research, develop and implement a novel workflow aimed to be easy to use and available to anyone who has access to a smartphone camera and 3D printing services. The developed workflow was used to manufacture two prototypes which proved valuable in the design iterations. As a result, an improved hinge was designed which has increased mechanical strength. Additionally, a smartphone photogrammetry validation study was included which provided preliminary results on the accuracy and precision. This novel measurement method has the potential to require little training and could be disseminated through video instructions posted online. The intention is to enable the patient to collect their own “3D scan” with the help of a friend or family member, effectively removing the need to book an appointment simply for collecting custom measurements. Lastly, it would allow the clinician to focus all their time on clinically relevant design tasks such as checking alignment, fit and comfort, which could all potentially be improved by adopting such digital methods. The ultimate vision for this work is to enable manufacturing of better custom knee braces at a reduce cost which are easily accessible for low-income populations.
135

Análise da confiabilidade inter e intra-examinador na avaliação postural pela fotogrametria computadorizada / Intra and Inter Observers Reliability Analysis Through Photogrammetry.

Iunes, Denise Hollanda 11 January 2005 (has links)
O propósito deste trabalho foi verificar a reprodutibilidade bem como a repetibilidade do método de avaliação postural por meio da fotogrametria computadorizada. Para isto 21 indivíduos, com idade 24,2 ± 1,3 anos de idade, foram fotografados em posição anterior, posterior, perfil e face. Para realização destas fotografias foram demarcados sobre a pele pontos anatômicos que são normalmente utilizados na avaliação postural tradicional. A partir destes pontos foram analisados diferentes ângulos através do aplicativo ALCimagem-2000. Para a análise interexaminador as fotos foram avaliadas por três examinadores diferentes e os resultados comparados. Para a análise intraexaminador as mesmas fotos foram avaliadas pelo mesmo examinador em duas ocasiões diferentes com um mês de intervalo. Para a análise da repetibilidade do método os voluntários foram fotografados duas vezes com intervalo de uma semana e as fotos avaliadas pelo mesmo examinador. Para comparação dos resultados intra e interexaminadores foram aplicados o coeficiente de correlação intraclasse. Os resultados revelaram que o método proposto apresenta significativa confiabilidade interexaminadores. Dos ângulos estatisticamente confiáveis, alguns tiveram menor coeficiente de confiabilidade, principalmente os ângulos do plano sagital referentes às curvaturas vertebrais, como lordose cervical, cifose torácica e lordose lombar. Na avaliação intra-examinador só não apresentou confiabilidade o ângulo da cifose torácica. Na repetibilidade do método somente o ângulo inferior da escápula não apresentou confiabilidade. Portanto, a fotogrametria computadorizada sugere ser um método confiável para avaliação postural no plano frontal anterior e posterior. Porém, para a análise no plano sagital necessita de mais estudos para definir parâmetros de normalidade das curvaturas vertebrais. / The purpose of this work was to verify the reproducibility, as well as the method repeatibility for postural evaluation through photogrammetry. For that, 21 individuals being 24,2 ??1,3 years old were photographed in anterior, posterior, profile and face positions. To perform these photos, several anatomic sites, which are often used in the traditional postural evaluation, were marked on the skin. Different angles from these sites were examined through the program ALCimagem-2000. For the inter-examiner analysis, the photos were evaluated by three different examiners whose results were compared. For the intra-examiner analysis, the same photos were evaluated by the same examiner in two different occasions. For the analysis of the repeatibility of the method, the volunteers were photographed twice with a period of a week interval, and the photos were evaluated by the same examiner. For comparing inter and intraexaminer results, the intra-class correlation coefficient was applied. The results revealed that the proposed method presented good inter-examiner reliability. From the statistically reliable angles, some had a lesser reliability coefficient, mainly the sagital plane angles referring to vertebral flexures such as the cervical lordosis, thoracic kyphosis, and lumbar lordosis. In the intra-examiner evaluation, just the thoracic kyphosis angle hasn\'t presented reliability. As for the repeatibility of the method just the inferior scapular angle haven\'t presented reliability. Thus, computerized photogrammetry seem be a reliable method for postural evaluation on the frontal, anterior and posterior planes. However, the sagital plane needs more studies to define normality parameters for the vertebral flexures.
136

Measuring and modeling the anisotropic, nonlinear and hysteretic behavior of woven fabrics

Williams, Robert W. 01 December 2010 (has links)
The computational modeling of clothing has received increasing attention since the late 1980's with the desire to study and animate clothing-wearer interactions. Within a clothing modeling framework, it is necessary to model the mechanical behavior of woven fabrics. An important aspect of modeling the mechanics of woven fabrics is capturing realistic stress-strain behaviors which are invariably anisotropic, nonlinear, and hysteretic in that they feature irrecoverable deformation when loadings are removed from the fabric. The objective of this research is to develop a fabric constitutive model that captures the primary features of anisotropy, nonlinearity, and hysteresis, and that can be easily implemented in a nonlinear, large deformation shell finite element framework for general clothing-wearer interaction modeling. To achieve the objective, biaxial responses of four different woven fabrics were experimentally measured under a battery of load-unload uniaxial stress tests performed in the fabrics' warp, weft, and bias 45° directions. Axial deformations were measured precisely using LVDTs, and transverse deformations were measured less precisely using photogrammetric methods. Such measurements yielded insight on the different fabrics' membrane properties such as nonlinear Young's moduli in the warp and weft directions, shear moduli, and Poisson's ratios. These membrane behaviors were captured in an incremental constitutive model that uses polynomial fitting of a fabric's loading warp and weft Young's moduli, and polynomial fitting of the membrane shear modulus. Measured membrane Poisson's ratios of the different fabrics were found to be asymmetrical and highly variable between fabric types. All of these effects were integrated in a nonsymmetrical incremental constitutive model that relates Piola-Kirchhoff stress to Green-Lagrangian strain. For numerical implementation in a shell finite element framework, the woven fabric's warp and weft directions relative to an individual element's lamina coordinate system are specified in the undeformed configuration of the fabric and are denoted as the local material coordinate system. As the fabric undergoes arbitrary deformations, the local Piola-Kirchoff stress, the Green-Lagrange strain, and its increment at a point in the fabric are transformed to the material coordinate system in which the stress is updated. The updated state of Piola-Kirchoff stress in the material coordinate system is then rotated back into the local lamina coordinate system for usage in finite element force and stiffness calculations. This new realistic material model for woven fabrics is successfully implemented and tested in a variety of computations such as simulation of quasi-static material tests, and dynamic fabric "drape" and "poke" tests.
137

Relative Orientation

Horn, Berthold K.P. 01 September 1987 (has links)
Before corresponding points in images taken with two cameras can be used to recover distances to objects in a scene, one has to determine the position and orientation of one camera relative to the other. This is the classic photogrammetric problem of relative orientation, central to the interpretation of binocular stereo information. Described here is a particularly simple iterative scheme for recovering relative orientation that, unlike existing methods, does not require a good initial guess for the baseline and the rotation.
138

Multi-modal registration of maxillodental CBCT and photogrammetry data over time

Bolandzadeh-Fasaie, Niousha 06 1900 (has links)
This thesis aims at introducing a methodology for clinical evaluation of orthodontic treatments using three-dimensional dento-maxillofacial images. Since complementary information is achieved by integrating multiple modalities, cone-beam computed tomography (CBCT) and stereophotogrammetry technologies are used to develop a methodology for tracking bone and facial skin variations over time. Our proposed methodology consists of a two-phase registration procedure. In the first phase, the multimodal images are registered using an extrinsic landmark-based registration followed by a robust Iterative Closest Points (ICP) method. In the second phase, by utilizing specific anatomical landmarks, single modal images of the skull and the mandible are registered over time using an intrinsic landmark-based registration method followed by the robust ICP algorithm. The results of registrations show that the signed error distribution of both mandible and skull registrations follow a normal distribution while all the errors fall within the CBCT precision range.
139

Observing Short-Term Geomorphic Change in a Human-Modified River Using Terrestrial Repeat Photographs and Traditional Surveys: Uncompahgre River, Colorado, USA

Depke, Tyler J. 2012 May 1900 (has links)
The Uncompahgre River in Ouray, CO, was modified in 1996 from a braided river system to a meandering river channel. Large boulders of riprap were placed along designed meanders to prevent erosion and enable the development of permanent human structures on the flood plain. Deposition of gravel bars in the modified channel occurs annually during the summer. This gravel is "mined" by the City of Ouray; however, the effects of this excavation and the original modification were never assessed. This study provides an assessment by quantifying cross-sectional area change, cumulative grain-size distributions, shear stresses, slopes, and sinuosities using traditional survey methods. In addition, volume change of a gravel bar inside the modified channel was estimated using extreme oblique photographs (>45 degrees from nadir) that were obtained from nearby cliffs. Close-range photogrammetry was used in the natural channel downstream to evaluate photogrammetric methods using different lenses, image sensors, and camera geometries. Both traditional and photogrammetric methods clearly indicated significant deposition in the modified channel, whereas erosion occurred directly downstream from the modified channel, but did not occur at a reach 1.5 km downstream. In the natural channel, no cross-sectional area change occurred, grains were poorly sorted, and the longitudinal slope was ~four times steeper than the modified channel. Shear stress ratios were used as an erosion threshold, which did not correlate with actual cross-sectional area change, but a decrease in shear stress ratios from May 2011 to September 2011 were associated with erosion. Average RMSE values for DEMs created from extremeoblique photographs of a gravel bar in May 2011 and September 2011 were 0.140 m and 0.324 m, respectively. Using a DEM of difference with a t-statistic filter revealed that 115m3 of gravel was deposited. The Uncompahgre River showed similar geomorphic characteristics to other rivers in southwest Colorado, however, the slope of the natural and modified channels were much steeper than other rivers. Extreme-oblique photography and unconventional sensors both yielded reliable results, showing that these atypical techniques can be used in terrestrial photogrammetric applications such as, post-restoration assessments, as long as proper base-to-height ratios are achieved.
140

Development Of Sled Range Test Facility For Store Separation Model

Ozyuksel, Alaettin Arda 01 June 2007 (has links) (PDF)
The aim of this thesis is to develop a test facility in order to validate the safe separation of a store model from the aircraft model with the analysis of the acquired data. Different alternatives are considered in the conceptual design and a facility is selected which contains the rail constructed 5 meters above the ground. 300 meter test range is used to accelerate the aircraft model, attached to the carriage with solid rocket engines. The concept is to accelerate the carriage within the first 100 meters, to perform the separation of the model at the desired velocity when the rocket engine is burned out, and in the last 100 meters, to decelerate the carriage in order to recover the models. After the parts of the carriage are designed with respect to the requirements of the separation and completing the similitude study of scaled models with the ratio of 1/8, separation tests are performed. These tests are constrained with 0.9 Mach due to the store and test aircraft limitations. Doppler radar is issued to measure the velocity and photogrammetry method is used to validate and analyze the separation and to obtain the vertical trajectory of the store model. Measured trajectory of the store model is compared with the trajectory of the full scale store.

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