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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.
11

The Relationship of the Sit and Reach Test to Criterion Measures of Hamstring and Back Flexibility in Adult Males and Females

Langford, Nancy Jane 08 1900 (has links)
The purpose of this study was to examine the criterion-related validity of the sit and reach test as a measure of hamstring and low back flexibility in adult males and females. Subjects were 52 males and 52 females, 20 to 45 years of age. Hamstring flexibility was measured using a goniometer. Spinal flexibility was measured using a tape measure and an inclinometer. The sit and reach test was performed according to the AAHPERD Health Related Fitness Test Manual. Data were analyzed using correlations and appropriate descriptive statistics. Conclusions of the investigation were: 1) in adult males 20 to 45, the sit and reach test is a valid measure of hamstring flexibility but has questionable validity as a measure of low back flexibility, 2) in adult females 20 to 45, the sit and reach test is a moderately valid measure of hamstring flexibility and is not a valid measure of low back flexibility.
12

The Analysis of Visual Motion: From Computational Theory to Neuronal Mechanisms

Hildreth, Ellen C., Koch, Christof 01 December 1986 (has links)
This paper reviews a number of aspects of visual motion analysis in biological systems from a computational perspective. We illustrate the kinds of insights that have been gained through computational studies and how these observations can be integrated with experimental studies from psychology and the neurosciences to understand the particular computations used by biological systems to analyze motion. The particular areas of motion analysis that we discuss include early motion detection and measurement, the optical flow computation, motion correspondence, the detection of motion discontinuities, and the recovery of three-dimensional structure from motion.
13

Valid motion estimation for super-resolution image reconstruction

Santoro, Michael 14 August 2012 (has links)
In this thesis, a block-based motion estimation algorithm suitable for Super-Resolution (SR) image reconstruction is introduced. The motion estimation problem is formulated as an energy minimization problem that consists of both a data and regularization term. To handle cases when motion estimation fails, a block-based validity method is introduced, and is shown to outperform all other validity methods in the literature in terms of hybrid de-interlacing. By combining the validity metric into the energy minimization framework, it is shown that 1) the motion vector error is made less sensitive to block size, 2) a more uniform distribution of motion-compensated blocks results, and 3) the overall motion vector error is reduced. The final motion estimation algorithm is shown to outperform several state-of-the-art motion estimation algorithms in terms of both endpoint error and interpolation error, and is one of the fastest algorithms in the Middlebury benchmark. With the new motion estimation algorithm and validity metric, it is shown that artifacts are virtually eliminated from the POCS-based reconstruction of the high-resolution image.
14

Tweel (TM) technology tires for wheelchairs and instrumentation for measuring everyday wheeled mobility

Meruani, Azeem 04 April 2007 (has links)
This thesis is focused on two aspects related to wheeled mobility: 1) Evaluating the impact of a new tire design on powered mobility, and 2) Instrumentation that permits better monitoring and assessment of wheeled mobility in everyday use. The Tweel technology tires developed by Michelin USA are comprised of an outer polyurethane ring supported by polyurethane fins instead of metal spokes, which allow the tire to deflect under pressure. As a wheelchair tire they offer a potential breakthrough as they have deflection properties similar to a pneumatic tire while maintaining the low maintenance of a solid foam-core tire. A study was conducted to compare the Tweel technology tires to standard solid foam-core tires for vibration transmission, traction and overall life span. The Tweel technology tires failed produce any significant difference in vibration transmitted to the user compared to solid foam-core tires. Additionally, the Tweel technology tires showed significant signs of deterioration after a month long field trial, thus indicating a short life span. However, Tweel technology tires provided better traction on both dry and wet concrete. Overall, Tweel technology tires have to be re-engineered to provide better damping properties, leading to lower vibrational levels transmitted to the user. The second section this thesis addressed the need to develop a methodology of measuring mobility in everyday usage. This section is part of a greater ongoing research project at CATEA (Center for Assistive Technology and Environmental Access) aimed at understanding everyday wheelchair usage. Methodology was developed to measure bouts of mobility that characterize wheelchair usage; which includes the number of starts, stops, turns and distance traveled through the day. Three different technologies which included, Accelerometer unit on the rim of the drive wheel, Gyro-Accelerometer unit on the frame of the chair and Reed switches, were tested. Testing included various criteria for accuracy, durability and compatibility for measuring bouts of everyday wheeled mobility. Although a single technology could not be used to measure all aspects of mobility, the Accelerometer unit on the rim met the design criteria for measuring starts stops and distance, while the Gyro-Accelerometer unit met the requirements for measuring turns.
15

Improving the Localization and Coverage of Colonoscopy with Motion Tracking and Surface Mapping

Phillips, Ian Hamilton Dale 24 November 2023 (has links)
Colonoscopy is essential for colorectal cancer screening and disease surveillance. It can remove pre-cancerous colon polyps to reduce a patient’s cancer risk. This thesis aims to improve colonoscopy’s localization using motion tracking and colonoscopy’s coverage using surface mapping. Chapter 4 describes an endoscope motion tracker that records the scope’s insertion length, rotation, and speed during a colonoscopy. The endoscope tracker’s motion record can be combined with the endoscope’s video to localize colon polyps or cancers. In the future, the device could record highly skilled manoeuvres performed by endoscopists to help train medical residents. It is difficult to image the colon’s mucosa because the colonoscope’s camera has a limited field of view. Chapter 3 uses a 180° fisheye camera to unwrap high resolution panoramas of a colon phantom. The panoramas are then combined into a mosaic map of the colon phantom’s surface. The colon’s surface is approximated as a cylinder. Follow up experiments could test our mapping algorithm using imagery from a wide-angle, high-definition colonoscope. Chapter 2 describes another technique to localize locations where polyps have been removed—blood vessel landmarks. Colonic blood vessels from a pig were imaged to determine if they could be used to fingerprint locations on the colon’s wall. Blood vessels are also useful image features for surface mapping. The proof-of-concept experiments successfully imaged large arteries but further work is needed to image the small capillaries in the colonic mucosa and to image the veins. In summary, we have visualized colonic blood vessels to test if they could be useful landmarks, tested using an extended field of view camera to create an unwrapped map of the colon wall, and designed an endoscope tracker to help localize abnormal tissue. Combining the endoscope tracker with the other two techniques should make is possible to accurately map the colon. / Thesis / Doctor of Philosophy (PhD) / Colonoscopy is a powerful tool for colon cancer screening. A colonoscopy can decrease the chance of developing advanced cancers by removing pre-cancerous polyps before they grow. This research works to improve colonoscopy’s localization using motion tracking and its coverage using surface mapping. We have developed an endoscope motion tracker that records the scope’s insertion length, rotation, and speed during a colonoscopy. It is In described in Chapter 4. The recorded motion can be combined with the endoscope’s video to improve colon cancer localization. Next, it is difficult to image the colon’s mucosa because the colonoscope’s camera has a limited field of view. Chapter 3 uses a 180° fisheye camera to unwrap high resolution panoramas of a colon phantom. The panoramas are then combined into a cylindrical surface map. Finally, Chapter 2 images the colon’s blood vessels to determine if they can fingerprint locations on the colon’s wall.
16

Algorithm-Based Efficient Approaches for Motion Estimation Systems

Lee, Teahyung 14 November 2007 (has links)
Algorithm-Based Efficient Approaches for Motion Estimation Systems Teahyung Lee 121 pages Directed by Dr. David V. Anderson This research addresses algorithms for efficient motion estimation systems. With the growth of wireless video system market, such as mobile imaging, digital still and video cameras, and video sensor network, low-power consumption is increasingly desirable for embedded video systems. Motion estimation typically needs considerable computations and is the basic block for many video applications. To implement low-power video systems using embedded devices and sensors, a CMOS imager has been developed that allows low-power computations on the focal plane. In this dissertation efficient motion estimation algorithms are presented to complement this platform. In the first part of dissertation we propose two algorithms regarding gradient-based optical flow estimation (OFE) to reduce computational complexity with high performance. The first is a checkerboard-type filtering (CBTF) algorithm for prefiltering and spatiotemporal derivative calculations. Another one is spatially recursive OFE frameworks using recursive LS (RLS) and/or matrix refinement to reduce the computational complexity for solving linear system of derivative values of image intensity in least-squares (LS)-OFE. From simulation results, CBTF and spatially recursive OFE show improved computational efficiency compared to conventional approaches with higher or similar performance. In the second part of dissertation we propose a new algorithm for video coding application to improve motion estimation and compensation performance in the wavelet domain. This new algorithm is for wavelet-based multi-resolution motion estimation (MRME) using temporal aliasing detection (TAD) to enhance rate-distortion (RD) performance under temporal aliasing noise. This technique gives competitive or better performance in terms of RD compared to conventional MRME and MRME with motion vector prediction through median filtering.
17

Identification of the glenohumeral joint rotation centre : an MRI validation study

Campbell, Amity January 2009 (has links)
[Truncated abstract] Normal and pathological upper limb movement assessments rely on the valid and reliable identification of the glenohumeral joint centre of rotation (GHJ). However, clarifying the most suitable techniques to identify and reference this location has proved a challenge, and performing a variety of methods that lack validation is commonplace. This may not only be erroneous, but also prevents the standardised collection of upper limb biomechanical information. The principle aim of this research was to clarify the accuracy and reliability of various methods of GHJ identification, including both predictive and functional techniques, as well as the error associated with referencing the GHJ location during dynamic movement trials. Predictive methods of GHJ identification rely on a generic relationship between the GHJ position and predetermined anatomical distances or locations. The ISB recommended predictive method was developed and validated using cadavers, and it appears that a number of convenient, yet to be validated methods are routinely performed in preference of this recommended technique. In the present study, magnetic resonance imaging (MRI) was utilised to validate, in vivo, the accuracy of various predictive approaches; the ISB recommended method and a representative sample of commonly used techniques. A new multiple linear regression model and simple 3D offset method, were developed from the MRI identified locations of the GHJ and the surface markers. The results indicated that the new multiple linear regression model (13 ±4.6) mm and simple 3D offset (12 ±4.6 mm) found an average GHJ location closer to the MRI determined location than any of the established predictive methods (14-50 mm), including the ISB recommended method (32 ±8.2 mm), and a recently publicised amended 2nd version (16 ±8.4 mm). ... For instance when the optimal algorithm (geometric sphere fit), marker set and movement trial were used in the functional approach, average in vivo accuracy errors of 27 ±8.6 mm were reported, around half the error reported by the most accurate and reliable predictive method (13 ±4.6 mm). A further investigation aimed to determine the most suitable location to reference the GHJ during dynamic motion analysis trials. The GHJ was referenced in a number of upper arm and acromion technical coordinate systems (TCSs) in a series of static MRIs. This permitted the error associated with each set of markers to be calculated in vivo. The results indicated that a combination of TCSs defined from two sets of markers; one placed on the acromial plateau and one located proximally on the upper arm, produced the most accurate results, recording an average of 18 ±4 mm of error following a large humeral elevation (up to 180°). Furthermore, a distal upper arm set of markers proved to be inappropriate for GHJ referencing, reporting average errors greater than 30 cm in two large humeral elevations. Therefore, following the identification of the GHJ, its 3D location should be referenced in the average of two TCSs determined from respective sets of markers placed on the acromion and proximal upper arm, during dynamic trials.
18

A Probing System with Replaceable Tips for Three Dimensional Nano-Metrology

Mrinalini, R Sri Muthu January 2017 (has links) (PDF)
With increase in the number of three dimensional (3-D) nanometer-scale objects that are being either fabricated or studied, there is a need to accurately characterize their geometry. While the Atomic force microscope (AFM) is a versatile tool for performing nano-metrology, it suffers from issues of poor accessibility of 3-D features and inability to measure 3-D forces that limit its applicability in 3-D nano-metrology. This thesis investigates the design and development of a novel probing system based on AFM that improves accessibility and enables direct measurement of 3-D forces acting on the AFM tip. Two approaches are investigated to address the issue of poor accessibility. The first is to develop a novel system that enables in-situ replacement and reuse of specialized AFM tips that improve accessibility, and the second is to design a special AFM tip that can actively re-orient about two independent axes. In order to perform in-situ tip replacement, a liquid meniscus based micro-gripper is developed and integrated on to a conventional AFM probe. The stiffness of the gripper is analyzed and shown to be adequately high along all three axes for AFM imaging to be performed. Tip replacement and re-use are both experimentally demonstrated by employing a novel tip-exchange station. The replaced tips are employed to show artifact-free AFM imaging of a standard calibration grating in both tapping-mode and contact-mode. To actively re-orient a conventional tip, a novel magnetically-actuated micro-scale ball-and-socket joint is integrated onto an AFM probe. The quasi-static behavior of the joint is experimentally characterized, and the ability of the tip to independently re-orient about two axes is demonstrated. The achieved range is about +/- 90 degrees about both X- and Y-axes. In order to realize the potential of the proposed probes for 3-D nano-metrology, an AFM is developed in-house that possesses the capability to make direct measurement of 3-D forces. Optimization of the measurement system to achieve identical sensitivities and resolution along all three axes is studied. Subsequently, the necessary electronics for measurement, actuation and control are developed. All the subsystems are experimentally calibrated and integrated. The overall AFM is shown to have a resolution of about 0.2 nm when operated in tapping-mode. The developed AFM is employed to showcase the following applications: characterization of the coefficient of kinetic friction of Muscovite mica, force controlled nano-scribing on polymethyl methacrylate (PMMA) and tapping-mode imaging of a calibration grating with the developed re-orientable AFM probe. Finally, the unique ability of the re-orientable AFM probe to control its tip-orientation is employed to develop a nanometer-scale coordinate measurement machine (CMM). The developed nano-CMM is shown to access the vertical wall of a sample and obtain its topography.
19

慣性センサを用いた手指の運動計測に関する研究 / カンセイ センサ オ モチイタ テユビ ノ ウンドウ ケイソク ニカンスル ケンキュウ

北野 敬祐, Keisuke Kitano 22 March 2019 (has links)
身体運動計測の重要性は増してきているが,作業で必須となる手指運動を精度良く計測することは困難である.本論文の目的は,手指運動計測システムを開発し,高精度な手指運動計測および解析手法を構築することである.そのため,手指運動計測用の慣性センサシステムを開発し,それに適した手指モデルの構築手法,計測誤差補正手法を提案,適用することで,より動作制約のない手指運動を精度良く計測,解析可能とする手法を構築した. / 博士(工学) / Doctor of Philosophy in Engineering / 同志社大学 / Doshisha University
20

Desenvolvimento de um goniômetro indutivo com bobinas ortogonais para aplicações biomédicas / Development of an inductive goniometer with orthogonal coils for biomedical applications

Turqueti, Carlos Augusto D'Orazio 31 August 2017 (has links)
Esta dissertação descreve o desenvolvimento de um goniômetro de enlace indutivo para medição de ângulos articulares. O goniômetro tem por objetivo medições de ângulos até 360° e a possibilidade de medição em articulações com mais de um grau de liberdade. Para isto utiliza como base o trabalho de Laskoski (2010) e os sistemas de navegação aeronáuticas. O experimento realizado por Laskoski (2010) efetua medições até 180° as bobinas precisam estar alinhadas. Os sistemas utilizados em navegações aeronáuticas utilizam a bússola eletrônica e o automatic direction finder, estes sistemas trabalham com grandezas na ordem de quilômetros. Este experimento visa adaptar os sistemas de navegação utilizando o campo magnético para poder efetuar medições de ângulo em pequenas distâncias. Os testes foram satisfatórios comparando os erros encontrados com os resultados dos experimentos de Laskoski (2010) e Carbonaro et al. (2014). O erro máximo em uma distância de 7,5 cm é de 10,6°e o desalinhamento entre a bobinas de +20° e -20° gera um erro de no máximo 1,71°. / This dissertation describes the development of an inductive goniometer for the measurement of joint angle. The goniometer aims to measure angles up to 360 ° and the possibility of measurement in joints with more than one degree of freedom. For this it uses as base the work of Laskoski (2010) and aeronautical navigation systems. The experiment performed by Laskoski (2010) makes measurements up to 180 ° and the coils need to be aligned. The systems used in aeronautical navigations use the electronic compass and the automatic direction finder, that systems work with magnitudes in the order of kilometers. This experiment aims to adapt the navigation systems using the magnetic field to be able to measure angles at small distances. The tests were satisfactory comparing the errors found with the results of the experiments of Laskoski (2010) and Carbonaro et al. (2014). The maximum error over a distance of 7.5 cm is 10.6 ° and the misalignment between the coils of + 20 ° and -20 ° generates an error of at most 1.71 °.

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