Dissertations / Theses on the topic 'Segmental motion'
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Breloff, Scott. "Quantifying Segmental Spinal Motion during Activities of Daily Living." Thesis, University of Oregon, 2013. http://hdl.handle.net/1794/13233.
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Back pain is a very common musculoskeletal impairment in most Americans. Average annual occurrence of back pain is reported around 30% of the population and is the most common cause of activity limitation in people younger than 45 years old. Eighty percent of the back pain presents in the lumbar spine. Although this ailment is very prevalent in the American population, there is a lack of empirical evidence supporting the common clinical diagnosis and intervention back pain strategies. The frequency of back pain and the lack of treatment methods were the motivation for this investigation. It is important to better understand spine dynamics during ambulatory tasks of daily activities to identify possible biomechanical mechanisms underlying back pain.
Current biomechanical quantification methods for spine dynamics are either too invasive or not detailed enough to fully comprehend detailed spinal movement. Therefore, a non-invasive but detailed procedure to calculate spine dynamics was developed and tested. In this study, multi-segmented spine dynamics (kinematics and kinetics) were calculated during four activities of daily living (level walking (W), obstacle crossing (OC), stair ascent (SA) and stair descent (SD)).
Our findings suggested an in-vivo multi-segmented spine surface marker set is able to detect different and repeatable motion patterns during walking among various spinal segments. The sacrum to lower lumbar (SLL) joint had the largest range of motion (ROM) when compared to the other more superior joints (lower lumbar to upper lumbar and upper lumbar to lower thoracic). Furthermore, SA task demonstrated more flexion ROM than both W and SD tasks. In addition to task influence, joints at different spine levels also demonstrated different ROMs, where SLL had a greater ROM than upper lumbar to lower thoracic (ULLT) in the transverse plane. Age was found to not significantly affect the segmental spinal ROM or peak angles. The vertical segmental joint reaction forces were different between tasks, where SD yielded larger vertical reaction forces than W.
Overall, findings from this dissertation work were able to show that a multi-segment spine marker system could be an effective tool in determining different spinal dynamics during various activities of daily living.
This dissertation includes unpublished co-authored material.
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Codreanu, Ion. "Evaluation of three dimensional segmental myocardial motion using cardiac magnetic resonance." Thesis, University of Oxford, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.670023.
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CATINO, LUIGI. "COMBINED STUDY OF SEGMENTAL MOTIONS AND THE MOTION OF THE BODY CENTER OF MASS DURING WALKING: NORMATIVE DATA AND APPLICATIONS TO FUNCTIONAL DIAGNOSIS AND TREATMENT IN REHABILITATION MEDICINE." Doctoral thesis, Università degli Studi di Milano, 2021. http://hdl.handle.net/2434/820051.
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In the present Thesis, walking was analyzed at various velocities in healthy participants, adults and children, on a split-belt treadmill mounted on 3D force sensors. Each belt can rotate at a different velocity, thus inducing artificial claudication. Conventional kinematic (optoelectronic) and surface EMG recordings from several lower limbs muscles were conducted. This experimental setting allowed to investigate both the motion of the body system as a whole (represented by its centre of mass, CoM) and the power provided by lower limb muscles (mostly, the plantar flexors). Various branches of an experimental campaign demonstrated that: a) a lateral shrinking of the CoM path is demonstrated with increasing age in children from 5 to 13 years. The lateral CoM oscillation/velocity function looks like a promising index of neural maturation. b) In adults, the 3D trajectory of the CoM implies a sharp U-turn (radius of curvature as small as 2 mm) at the beginning of the left-to-right (or vice-versa) oscillation, implying demanding muscular coordination. This curvature looks like a promising index of balance during walking. c) The claudication induced by “split” walking causes temporal asymmetries (“escape limp”) analogous to those found in pathologic claudication (shorter stance time, on the faster belt) but opposite spatial and dynamic asymmetries (longer posterior step and higher pantar flexors’ power, on the faster belt). d) The average velocity of the CoM on split-belt treadmills is different from the mean velocity between the belts. This velocity depends on the time spent by the point of application of the resulting ground reaction force on either belt. This implies that errors were made in the Literature, comparing split walking with tied walking at the mean velocity between the two belts. e) A representative unilaterally paretic patient has been analyzed to give an idea of the feasibility and the potential usefulness of the combined segmental and CoM analysis on split-belt treadmills. Overall, the series of experiments paves the way to a more soundly based analysis of pathologic gaits.
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Denoziere, Guilhem. "Numerical Modeling of a Ligamentous Lumbar Motion Segment." Thesis, Georgia Institute of Technology, 2004. http://hdl.handle.net/1853/4998.
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Eight out of ten people in the United States will have problems with low back pain at some point in their life. The most significant surgical treatments for low back pain can be distributed into two main groups of solutions: arthrodesis and arthroplasty. Spinal arthrodesis consists of the fusion of a degenerated functional spine unit (FSU) to alleviate pain and prevent mechanical instability. Spinal arthroplasty consists of the implantation of an artificial disc to restore the functionality of the degenerated FSU. The objective of this study is to analyze and compare the alteration of the biomechanics of the lumbar spine treated either by arthrodesis or arthroplasty.
A three-dimensional finite element model of a ligamentous lumbar motion segment, constituted of two FSUs, was built and simulated through a static analysis with the finite element software ABAQUS.
It was shown that the mobility of the segment treated by arthrodesis was reduced in all rotational degrees of freedom by an average of approximately 44%, relative to the healthy model. Conversely, the mobility of the segment treated by arthroplasty was increased in all rotational degrees of freedom by an average of approximately 52%. The FSU implanted with the artificial disc showed a high risk of instability and further degeneration. The mobility and the stresses in the healthy FSU, adjacent to the restored FSU in the segment treated by arthroplasty, were also increased.
In conclusion, the simulation of the arthroplasty model showed more risks of instability and further degeneration, on the treated level as well as on the adjacent levels, than in the arthrodesis model.
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Gibson, Thomas J. Graduate School of Biomedical Engineering Faculty of Engineering UNSW. "Development and validation of a C5/C6 motion segment model." Awarded by:University of New South Wales. Graduate School of Biomedical Engineering, 2006. http://handle.unsw.edu.au/1959.4/23086.
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There is a large body of work investigating whiplash-associated injury in motor vehicles and its causation. Being unable to detect the actual injury and having to use the symptoms of the sufferer as a surrogate has made progress in understanding the injury causation slow. Still lacking are the causal relationships between the biomechanical load on the vehicle occupant in the crash, the resulting loading on the neck and the actual injuries suffered. The optimisation of the design of vehicle safety systems to minimise whiplash needs a better understanding of human tolerance to these injuries. This thesis describes the development of a mathematical multi-body C5/C6 motion segment model to investigate the causation of soft-tissue neck injury. This model was validated with available static in-vitro experimental data on excised motion-segments and then integrated into the existing, validated multi-body human head and neck model developed by van der Horst, to allow the application of realistic dynamic loads. The responses and injury sensing capability of the C5/C6 model were compared with available data for volunteers and cadavers in rear impacts. The head and neck model was applied to the investigation of a group of real rear impact crashes (n = 78) of vehicles equipped with a crash-pulse recorder and with known postcrash injury outcomes. The motion of the occupants in these crashes had previously been reconstructed with a MADYMO BioRID II dummy-in-seat model validated by sled testing. The occupant T1 accelerations from these reconstructions were used to drive the head and neck model. The soft-tissue loading at C5/C6 of the head and neck model was analysed during the early stage of the impact, prior to contact with the head restraint. The loading and the pain outcome from the vehicle occupants in the actual crash were compared statistically. For the longer-term whiplash-associated pain outcomes (of greater than 1 month duration) for these occupants, the C5/C6 model indicated good correlation with the magnitude of the shear loading on the facet capsule. In lower severity impacts, the model result supported a second hypothesis of injury to this motion segment: facet surface impingement.
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Chang, Song. "Kinematics and motion planning of a multi-segment wheeled robotic vehicle." Ohio : Ohio University, 1994. http://www.ohiolink.edu/etd/view.cgi?ohiou1176839544.
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Valentová, Jana. "Motivy vybraných segmentů cestovního ruchu k návštěvě České republiky." Doctoral thesis, Vysoká škola ekonomická v Praze, 2011. http://www.nusl.cz/ntk/nusl-199596.
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This Ph.D. thesis is aimed at inbound tourism in the Czech Republic, analysis of statistical data and their development in the period of years 2004 -- 2013, characteristics of the main source markets for the Czech Republic, and analysis of motives regarding participants of outbound tourism to the Czech Republic in the observed countries. The principal aim is to analyze and compare intensity of motives of the selected geographic, demographic, socio-economic, and behavioral segments for visits to the Czech Republic. An integral part of the aim is to suggest further possibilities of the motivation research and their exploitation in the marketing practice of the tourism industry. The author defines all theoretical terms closely connected with the tourism market segmentation, motives and motivations to travel including interesting view of them throughout history. It is evident that the travel motives influenced by various factors are differentiated parallely with the human society development. The author characterizes the Czech Republic destination offer and evaluates its inbound tourism in the period of years 2004 -- 2013 by means of 4 main indicators: number of guests, number of overnight stays, average length of stay, foreign currency incomes. The author also evaluates the researches focused on perception of the Czech Republic abroad that was carried out by the institutions representing the Czech Republic abroad. The detailed analysis of travel motivations was performed by the author herself in the form of questionnaires. Results of these analyses bring impulses to other possibilities of the research in the field of inbound tourism not only in the academic sphere but also in research work of state and public authorities, and in practice when creating tourism products and communications mix.
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Martinez, Lozada Francisco Mauricio. "The effects of L4/5 fusion on the adjacent segments in the lumbar spine." Thesis, University of Manchester, 2016. https://www.research.manchester.ac.uk/portal/en/theses/the-effects-of-l45-fusion-on-the-adjacent-segments-in-the-lumbar-spine(1b88de80-7c39-4646-860d-7312ca21d947).html.
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Lumbar intervertebral disc disorder is a spinal condition that affects the normal function of the intervertebral discs mainly due to the natural aging process. This condition can manifest itself in pain and limited motion in the legs, amongst others. Posterolateral Fusion (PLF) and Posterior Lumbar Interbody Fusion (PLIF) are two of the most used surgical procedures for treating lumbar intervertebral disc disease. Although these procedures are commonly used and performed successfully the impact in terms of the stresses developed in the posterior implants employed and in the spinal components adjacent to the surgical site has not been exhaustively investigated. In addition, the consequences of the procedure on the reduction of the Range of Motion of the lumbar spine is not clearly understood. The objective of this research is to investigate the effect of one-level spinal fusion of lumbar segment L4-L5 on the stresses and the range of motion at the remaining, adjacent lumbar levels. Four 3 dimensional finite element models of a lumbosacral spine were created from Computer Tomography data (CT scan). The models were used to investigate four surgical scenarios, including the use of 0o and 4o interbody cages, in addition to the un-instrumented spine for flexion, extension, torsion and lateral bending motions. The predictions obtained from the models enabled the mechanical behaviour of the lumbar spine following fusion surgery using 0 o and 4o cages to be investigated and compared. In addition, a clinical study was performed to quantify the reduction in the range of motion for subjects who had undergone L4/5 posterior lumbar interbody fusion surgery. The clinical results were compared to those of subjects who had not undergone surgery and to the range of motion predictions from the computational model. The results from this research demonstrate that the insertion of posterior instrumentation does not have an impact on the spinal structures above the L3/4 intervertebral disc. However, the pedicle screws and the insertion of the interbody cages causes stress levels in the area adjacent to the surgical site to rise which could promote accelerated degeneration of the discs. Additionally, this study demonstrates how the pedicle screws are affected by the surgical spinal fusion techniques. Furthermore, the investigation demonstrates how posterior lumbar interbody fusion causes the range of motion of patients that had undergone this surgery to decrease. The results from the comparison of the behaviour of the use of 0º and 4º interbody cages in L4-5 posterolateral fusion demonstrates that the stress levels in the adjacent vertebrae, intervertebral discs and pedicle screw fixation system increase when 4º are used cages than when 0º cages were employed. The results from the in-vitro study show a decrease in the range of motion of the subjects who had undergone L4/5 posterior lumbar interbody fusion surgery when compared with the subjects with no low back pain history. This indicates that the PLIF surgery combined with the normal disc degeneration is subjected to higher stresses than the healthy spine.
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Yingling, Vanessa Rose. "Shear loading of the lumbar spine, modulators of motion segment tolerance and the resulting injuries." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq22252.pdf.
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Seenivasan, Gopi. "Application of adaptive bone remodelling theory to the motion segments of lumbar spine: a theoretical study." Thesis, University of Iowa, 1993. https://ir.uiowa.edu/etd/5699.
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Sterner, Jay. "SMARTPHONE-TAPE METHOD FOR CALCULATING BODY SEGMENT INERTIAL PARAMETERS FOR ANALYSIS OF PITCHING ARM KINETICS." DigitalCommons@CalPoly, 2020. https://digitalcommons.calpoly.edu/theses/2133.
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The objectives of this study were to (1) develop a non-invasive method (referred to as Smart Photo-Tape) to calculate participant-specific upper arm, forearm, and hand segment inertial properties (SIPs) (e.g. mass, center of mass, and radii of gyration) and (2) use those Smart Photo-Tape properties in inverse dynamics (ID) analyses to calculate injury-related pitching arm kinetics. Five 20- to 23- year-old baseball pitchers were photographed holding a baseball and analyzed using the Smart Photo-Tape method to obtain 3-D inertial properties for their upper arm, forearm, and hand. The upper arm and forearm segments were modelled as stacked elliptic cylinders and the hand was modelled as an ellipsoid. One participant received a dual energy x-ray absorptiometry (DXA) scan and conducted a motion analysis study, pitching 10 fastballs. Scaled SIPs from cadaver studies and Smart Photo-Tape SIPs were compared using one sample t-tests. Pitching arm kinetic predictions were calculated and compared using scaled inverse dynamics (ID), Smart Hand ID (a combination of scaled SIPs for the upper arm and forearm and Smart Photo-Tape SIPs for the hand), and Smart Photo-Tape ID. The major result was that the Smart Photo-Tape SIPs were significantly different when compared to their respective scaled inertial properties, with the hand segment producing the largest difference between the scaled SIPs and Smart Photo-Tape SIPs. The implication of this study is that researches or coaches can use the Smart Photo-Tape method to calculate participant specific SIPs for pitching arm kinetic analysis.
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Splittstoesser, Riley Emiel. "A simple method for predicting dynamic lumbar motion segment angles using measures of trunk angle and subject anthropomentry." The Ohio State University, 2001. http://rave.ohiolink.edu/etdc/view?acc_num=osu1302112152.
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Perin, Andrea. "A contribuição de diversos segmentos corporais na execução do teste sentar e alcançar." Universidade Tecnológica Federal do Paraná, 2013. http://repositorio.utfpr.edu.br/jspui/handle/1/489.
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O Teste de Sentar e Alcançar (TSA) é o teste mais utilizado para avaliação de flexibilidade dos isquiotibiais, contudo, alguns fatores influenciam o seu resultado como o comportamento da coluna vertebral. Esta pesquisa objetiva determinar a contribuição da articulação do quadril, da coluna lombar e da coluna torácica na execução do TSA em jovens brasileiros. Foi realizado um estudo observacional descritivo com uma amostra composta por 195 rapazes de 18 a 19 anos. Para identificar a contribuição dos segmentos corporais no movimento de flexão do tronco, realizou-se juntamente com o TSA uma análise cinemática angular por meio de Fotogrametria. Para tanto, foi desenvolvido um protocolo de avaliação de ângulos de referência que foram transformados em percentuais de contribuição dos segmentos. Os ângulos e percentuais foram classificados em dois padrões de referência do TSA, os quais permitiram identificar que quanto melhor a classificação no TSA, maior a utilização do quadril e menor a utilização da coluna torácica. A coluna lombar manteve-se estável durante o movimento. Os ângulos e percentuais foram classificados também nas categorias de IMC, revelando que indivíduos obesos utilizam mais o quadril para realizar o movimento, pois não conseguem fazer compensação com a coluna torácica. Com base nos resultados, foi possível criar uma tabela de classificação dos ângulos e percentuais, que permitiu identificar compensações e padrões de movimento conforme a condição das musculaturas envolvidas. Pôde-se concluir que as contribuições médias da coluna torácica, da coluna lombar e do quadril na realização do TSA são respectivamente: 46,014%, 12,676%, 41,309%. Entretanto, a medida do TSA propriamente dita não permite esse detalhamento, pois seu resultado faz referência à flexão total do tronco juntamente com a flexão do quadril. Assim, recomenda-se que a avaliação da flexão da coluna torácica, da coluna lombar e do quadril seja realizada separadamente, por fotogrametria, com base no protocolo e parâmetros médios estabelecidos neste estudo, por meio da classificação de seus valores nas categorias propostas.The Sit and Reach Test (SR) is the most widely used assessment of hamstrings flexibility, however, some factors can influence their results as a behavior of the spine. This research aims to determine the contribution of the hip joint, of the lumbar and thoracic spine in the execution of SR in young Brazilians. The descriptive observational study subjects were 195 young men from 18 to 19 years. To identify the contribution of body segments in flexion of the trunk it was evaluated the SR together with angular kinematic analysis through of Photogrammetry. To that end, we developed a protocol for evaluating reference angles that were transformed into percentage contribution of the segments. The angles and percentages were classified into two reference standards of the SR, which identified that the best ranking in SR, greater use of hip and lower utilization of the thoracic spine. The lumbar spine was stable during movement. The angles and percentages were also classified in the categories of BMI, revealing that obese people use more hip to perform the movement, because they cannot make compensation with thoracic spine. Based on the results, it was possible to create a table of classification of angles and percentages, which allowed for the identification and compensation movement patterns in accordance with the condition of the muscles involved. It can be concluded the contributions of the thoracic spine, lumbar spine and hip in performing the SR are respectively 46.014%, 12.676%, 41.309%. However, only the measure of the SR does not permit this detail because its result refers to the total trunk flexion and hip flexion. Thus, it is recommended that evaluation of flexion of the thoracic spine, lumbar spine and hip joint are performed separately by photogrammetry, based on the average parameters and protocol established in this study, through the classification of their values in the proposed categories.
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Henault, German A. "A computer simulation study and component evaluation for a quaternion filter for sourceless tracking of human limb segment motion." Thesis, Monterey, California. Naval Postgraduate School, 1997. http://hdl.handle.net/10945/26425.
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Approved for public release; distribution is unlimited.Current methods of tracking the human body within virtual environments (VE) are hampered by problems due to interference which occurs from using artificially generated source signals. In recent years, the miniaturization of self-contained inertial tracking systems has made them a viable alternative. They are impervious to external interference but require filtering in order to give accurate orientation data. Filters for this purpose using Euler angles are common, but are limited by their inability to track through the vertical axis. A filter based on quaternions would not have this limitation. This thesis presents an implementation of a quaternion filter in Lisp. The filter was tested with a computer simulated inertial tracker. Also presented is a quantitative and qualitative assessment of an existing inertial tracker, Angularis, which uses a filter based on Euler angles. This effort resulted in an improved filter based on quaternions which allows objects to be tracked through the vertical axis making it a more desirable option for body tracking applications. The evaluation of the Angularis inertial tracker yielded generally good results when tested on a tilt-table at various rates of motion through 45 degrees of rotation. Specifically, orientation errors measured were typically less than one degree for smooth motion. However, when moved rapidly through large orientation angles, it was found that the nonlinear characteristic of the proprietary filter resulted in large steady state errors
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Kumar, Bharathwaj. "Determination of Biomechanical Properties and Mechanobiological Behavior of a Spinal Motion Segment with Scoliosis Treatment Using Finite Element Analysis." University of Cincinnati / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1303843363.
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Mosaddegh, Saleh. "Two View Line-Based Matching, Motion Estimation and Reconstruction for Central Imaging Systems." Phd thesis, Université de Bourgogne, 2011. http://tel.archives-ouvertes.fr/tel-00799337.
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The primary goal of this thesis is to develop generic motion and structure algorithms for images taken from constructed scenes by various types of central imaging systems including perspective, fish-eye and catadioptric systems. As-suming that the mapping between the image pixels and their 3D rays in space is known, instead of image planes, we work on image spheres (projection of the images on a unit sphere) which enable us to present points over the entire viewsphere suitable for presenting omnidirectional images. In the first part of this thesis, we develop a generic and simple line matching approach for images taken from constructed scenes under a short baseline motion as well as a fast and original geometric constraint for matching lines in planar constructed scenes insensible to the motion of the camera for all types of centralimages including omnidirectional images.Next, we introduce a unique and efficient way of computing overlap between two segments on perspective images which considerably decreases the over all computational time of a segment-based motion estimation and reconstruction algorithm. Finally in last part of this thesis, we develop a simple motion estima-tion and surface reconstruction algorithm for piecewise planar scenes applicable to all kinds of central images which uses only two images and is based on mini-mum line correspondences.To demonstrate the performance of these algorithms we experiment withvarious real images taken by a simple perspective camera, a fish-eye lens, and two different kinds of paracatadioptric sensors, the first one is a folded catadioptric camera and the second one is a classic paracatadioptric system composed of a parabolic mirror in front of a telecentric lens.
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Khoshnoudirad, Daniel. "Aspects combinatoires des motifs linéaires en géométrie discrète." Thesis, Paris Est, 2016. http://www.theses.fr/2016PESC1046.
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La Géométrie Discrète, comme Science de l'Informatique Théorique, étudie notamment les motifs linéaires tels que les primitives discrètes apparaissant dans les images : les droites discrètes, les segments discrets, les plans discrets, les morceaux de plans discrets par exemple. Dans ce travail, je me concentre tout particulièrement sur les diagrammes de Farey qui apparaissent lors de l'étude des primitives discrètes que sont les (m,n)-cubes, autrement dit les morceaux de plans discrets. J’étudie notamment la Combinatoire des droites formant les diagrammes de Farey, en établissant des formules exactes. Je montre alors que certaines méthodes utilisées auparavant ne permettront pas d'optimiser la Combinatoire des (m,n)-cubes. J'obtiens aussi une estimation asymptotique en utilisant la Théorie des Nombres Combinatoire. Puis, concernant les sommets apparaissant dans les diagrammes de Farey, j'obtiens une borne inférieure. J'analyse alors les stratégies déjà mises en place pour l'étude des $(m,n)$-cubes par les seuls diagrammes de Farey en deux dimensions. Afin d'obtenir de nouvelles bornes plus précises pour les $(m,n)$-cubes, une des seules méthodes actuellement existantes, est de proposer une généralisation de la notion de pré image d'un segment discret, à celle de pré image d'un $(m,n)$-cube, avec pour conséquence une nouvelle inégalité combinatoire sur le cardinal des (m,n)-cubes (inégalité qui pourrait même s'avérer être une égalité). Ainsi, nous introduisons la notion de diagramme de Farey en trois dimensionsDiscrete Geometry, as Theoretical Computer Science, studies in particular linear patterns such as discrete primitives in images: the discrete lines, discrete segments, the discrete planes, pieces of discrete planes, for example. In this work, I particularly focused on Farey diagrams that appear in the study of the $ (m, n) $ - cubes, ie the pieces of discrete planes. Among others, I study the Combinatorics of the Farey lines forming diagram Farey, establishing exact formulas. I also get an asymptotic estimate using Combinatorial Number Theory. Then, I get a lower bound for the cardinality of the Farey vertices. After that, we analyze the strategies used in the literature for the study of (m, n)- cubes only by Farey diagrams in two dimensions. In order to get new and more accurate bounds for (m, n)- cubes, one of the few available methods, is to propose a generalization for the concept of preimage of a discrete segment for (m, n) - cube, resulting in a new combinatorial inequality. Thus, we introduce the notion Farey diagram in three dimensions
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Wang, Jaw-Lin. "Development of a Viscoelastic Finite Element Model of L2-L3 Motion Segment: Towards Quantification of Dynamic Risk Factors for Industrial Low Back Disorders /." The Ohio State University, 1996. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487935125881785.
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Santos, Rodrigo Silva e. [UNESP]. "Caracterização da rigidez póstero-anterior da coluna lombar in vivo: uma análise biomecânica." Universidade Estadual Paulista (UNESP), 2007. http://hdl.handle.net/11449/105354.
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A mobilização póstero-anterior consiste numa técnica de terapia manual que tem a finalidade de detectar alterações no padrão normal e na amplitude dos movimentos das articulações intervertebrais em pacientes com lombalgia. Mecanicamente, define-se como uma sobrecarga de inclinação de três pontos e, embora, o procedimento de aplicação desta técnica tenha sido descrito, caracteriza-se por um método subjetivo de análise clínica. No sentido de buscar um melhor esclarecimento acerca dos aspectos mecânicos envolvidos na mobilização póstero-anterior, foi desenvolvido um dispositivo eletromecânico, para análise in vivo da rigidez segmentar póstero-anterior da coluna lombar. Tal aparato compõe-se essencialmente de um suporte de sustentação com dois graus de liberdade (x, y) integrado a um motoredutor de corrente contínua acoplado a um pino guia e fixo a uma maca especialmente adaptada. Permite o controle preciso da intensidade, direção e velocidade da força aplicada, além da mensuração da amplitude do deslocamento intervertebral. Os resultados demonstraram que o instrumento desenvolvido apresenta a possibilidade de uma análise quantitativa acurada, em termos de rigidez segmentar na coluna lombar, indicando um grau de confiabilidade significativo para os dados obtidos em testes de repetibilidade (ICC > 0,80). Foi demonstrado haver diferença estatisticamente significativa (p<0,05) entre os valores médios dos graus de rigidez dos níveis vertebrais analisados (LI, LII, LIII, LIV e LV) em 10 sujeitos avaliados. Deste modo, é importante que seja questionado o conceito da comparação do grau de rigidez entre os diferentes níveis vertebrais, num mesmo sujeito, para critério de diagnóstico.
The posteroanterior motion test consists of a manual therapy technique to assess the range of motion and stiffness parameters of intervertebral joints in subjects with low back pain. Mechanically, it is defined as a three point bending loading. Although, has been described the technique procedure of the posteroanterior motion test, it is characterized by a subjective method of clinical analysis. In the quest to better understand concerning the mechanical aspects of posteroanterior motion test was developed a mechanical device for assessment the response of the lumbar spine to a posteroanterior pressure in vivo. Essentially, such apparatus is composed of a sustentation support with two degrees of freedom (x, y) fixed to a couch especially adapted and integrated to a continuous current motor and a guidance pin. It allows variables such as force, frequency of oscillation and displacement to be precisely controlled. The results demonstrated high reliability (ICC > 0,80) of the measures obtained in test and re-test. So, the instrument developed presents the prospect of an accuracy quantitative analysis of intervertebral posteroanterior stiffness in lumbar spine. There was statistically significant difference (p<0,05) amongst the means of stiffness coefficients of the vertebral levels analyzed (LI, LII, LIII, LIV and LV) in 10 subjects evaluated. Therefore, its is important to be questioned the concept of the comparison of stiffness in different vertebral levels in a same subject for diagnosis criterion.
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Carter, Sarah Louise. "Lower leg and foot contributions to turnout in pre-professional female dancers: A clinical and kinematic analysis." Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2018. https://ro.ecu.edu.au/theses/2101.
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Turnout, the act of externally rotating the legs, is produced through the summation of joint structure characteristics and ranges of motion at the hip, knee, ankle and foot. The hip joint’s contribution to functional turnout, a dancer’s preferred turnout stance, has received extensive examination, whereas little is known about below-the-hip contributions. Dancers with limited hip external rotation (HER) are associated with an increased risk of overuse lower limb injury. These injuries have been attributed to forcing turnout via additional external tibiofemoral rotation (TFR) and foot pronation. Yet knowledge of these compensatory mechanisms is based on biomechanical theories and clinical observations rather than quantitative clinical assessments or 3D motion analysis. The principal aim of this research was to investigate the lower leg and foot contributions to turnout in university-level female dancers using quantitative clinical assessments and 3D motion analysis, as well as the compensations mechanisms dancers use to increase turnout.
The first study focused on assessing the lower leg and foot contributions to turnout using the clinical assessments of passive TFR and active measures of foot pronation in turnout. The results showed dancers assumed a more pronated posture in turnout, and those with a greater passive TFR demonstrated a less pronated position in turnout providing new insight into the mechanical coupling between the foot and the tibiofemoral joint in dancers.
The purpose of the second study was to use 3D kinematic analyses to determine the lower leg and foot compensations that dancers use to accentuate their turnout. Active and passive TFR of the dancers was also measured. The results demonstrated foot abduction was the strongest predictor of functional and forced turnout, compared to both the hip and knee external rotation. A moderate-strong negative relationship was observed between HER and foot abduction in all turnout conditions. A moderate negative relationship was found between the passive TFR and foot abduction in all turnout conditions. These findings indicate clinical measures of external tibiofemoral rotation can predict the total below-hip compensation mechanisms a dancer uses to achieve turnout. Suggesting, dancers are more likely to pronate about the foot/ankle complex, than rotate at the knee to compensate for limited HER. Whereas dancers with less foot mobility may force additional rotation via the knee which may contribute to rotational knee joint laxity.
The previous study provided the rational for an in-depth analysis of the foot/ankle complex such as that provided by three-dimensional multi-segment foot models (3DMFMs). The lack of an appropriate model for ballet dancers led to the modification of the Rizzoli Foot Model. Kinematic repeatability of the model was determined from analysing ballet dancers performing the following movements; parallel stance, turnout plié, turnout stance, turnout rise and flex-point-flex. First metatarsophalangeal joint (MTPJ) in the sagittal plane demonstrated excellent intra and inter-assessor repeatability across all movements. All inter-segmental angles except for the tibia-hindfoot and hindfoot-midfoot frontal planes demonstrated excellent intra-assessor repeatability during flex-point-flex movements. Providing a reliable method to measure 3D foot/ankle complex can enable a deeper understanding of the foot/ankle complex contribution to turnout. Previous 3DMFM used in dance science consisted of only two foot segments, hindfoot and forefoot whereas this model includes a midfoot segment which is important as forefoot abduction has been suggested to give the illusion of a larger turnout angle.
The final study aimed to examine the lower leg and foot compensations that dancers use to accentuate their turnout using a dance specific 3DMFM. Hindfoot abduction and eversion were the strongest predictors of foot abduction in turnout. Midfoot abduction was significantly greater in forced turnout compared to functional turnout. No significant differences were found for forefoot abduction, first MTPJ abduction and navicular drop in functional or forced turnout, compared to natural stance. Foot pronation does play a role in achieving turnout and there may be a safe range of pronation. However, the amount of detrimental pronation for a dancer is unknown. The overall results from these studies offer compelling evidence that the foot/ankle complex plays a more important role in achieving turnout, than previously thought. Further prospective research on in situ measures of the lower leg and foot in turnout and injury surveillance are required to improve our understanding of the normal and abnormal dance biomechanics.
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Levendoglu, Mert. "Probabilistic Seismic Hazard Assessment Of Ilgaz - Abant Segments Of North Anatolian Fault Using Improved Seismic Source Models." Master's thesis, METU, 2013. http://etd.lib.metu.edu.tr/upload/12615430/index.pdf.
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Bolu-Ilgaz region was damaged by several large earthquakes in the last century and the
structural damage was substantial especially after the 1944 and 1999 earthquakes. The
objective of this study is to build the seismic source characterization model for the rupture
zone of 1944 Bolu-Gerede earthquake and perform probabilistic seismic hazard assessment
(PSHA) in the region. One of the major improvements over the previous PSHA practices
accomplished in this study is the development of advanced seismic source models in terms
of source geometry and reoccurrence relations. Geometry of the linear fault segments are
determined and incorporated with the help of available fault maps. Composite magnitude
distribution model is used to properly represent the characteristic behavior of NAF without an
additional background zone. Fault segments, rupture sources, rupture scenarios and fault
rupture models are determined using the WG-2003 terminology. The Turkey-Adjusted NGAW1
(Gülerce et al., 2013) prediction models are employed for the first time on NAF system. The results of the study is presented in terms of hazard curves, deaggregation of the hazard and uniform hazard spectrum for four main locations in the region to provide basis for evaluation of the seismic design of special structures in the area. Hazard maps of the region for rock site conditions and for the proposed site characterization model are provided to allow the user perform site-specific hazard assessment for local site conditions and develop site-specific design spectrum. The results of the study will be useful to manage the future seismic hazard in the region.
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NASIM, AMNAH. "Adaptation of the Segmented Beat Modulation Method to support diagnosis of cardiovascular disorders using electrocardiographic tracings acquired by wearable sensors." Doctoral thesis, Università Politecnica delle Marche, 2021. http://hdl.handle.net/11566/285589.
Full textAbstract:
Lo scopo di questa tesi è adattare il Segmented Beat Modulation Method (SBMM), un metodo per il filtraggio di segnali electrocardiografici (ECG), per tenere conto sia dei ritmi cardiaci sinusali che non e per aumentare la sua usabilità includendo i moderni sensori indossabili oltre ai tradizionali dispositivi clinici per la diagnosi di patologie cardiovascolari. Infatti, SBMM non è attualmente in grado di funzionare in presenza di battiti cardiaci anormali o aritmici (eventi critici che potrebbero portare allaa morte cardiaca improvvisa), il che limita enormemente la sua applicabilità alla diagnosi di malattie cardiovascolari in uno scenario reale. A questo scopo, questo lavoro presenta il Extended Segmented Beat Modulation Method (ESBMM) con una funzione di classificazione del battito cardiaco utilizzando la convolutional neural network (CNN) che separa prima i battiti cardiaci normali da quelli sopraventricolari (S) e ventricolari (V), e in secondo luogo utilizza modelli rappresentativi mediani separati per filtrare e ricostruire la registrazione ECG pulita. Nel complesso, l’accuratezza (Ac) della classificazione CNN era del 91,5% mentre i valori di predizione positive erano del 92,8%, 95,6% e 83,6%, rispettivamente per le classi di battito N, S e V. Alla fine, il miglioramento del rapporto segnale-rumore (SNR) è stato inferiore a 2 dB in presenza di livelli di rumore trascurabile, ma è aumentato in presenza di rumore fino a superare i 5 dB in presenza di artefatti da movimento degli elettrodi. Pertanto, ESBMM si è dimostrato uno strumento affidabile per classificare i battiti cardiaci in classi N, S e V e per filtraggio di tracciati ECG caratterizzati da ritmi sia sinusali che non sinusali mantenendo la variabilità morfologica nel segnale ECG pseudo-periodico. Altri miglioramenti proposti a SBMM sono un test di compressione preliminare che utilizza la trasformata coseno discreta. Il metodo viene valutato utilizzando SNR e il rapport di compressione (CR) considerando diversi livelli di energia del segnale ECG ricostruito. Per il filtraggio, è stato raggiunto un SNR medio di 4,56 dB che rappresenta un calo complessivo medio di 1,68 dB (37,9%) rispetto all'elaborazione del segnale non compresso mentre il 95% dell'energia del segnale è intatto e quantizzato a 6 bit per la memorizzazione del segnale (CR=2) rispetto ai 12 bit originali, con conseguente riduzione del 50% delle dimensioni di archiviazione. Un altro miglioramento è l’adattamento dell'SBMM alla frequenza cardiaca in modo dinamico ogni 20 secondi, particolarmente indicato per l'acquisizione di dati ECG a lungo termine. Un altro miglioramento presentato adatta SBMM al moderno hardware veloce utilizzando la tecnica di vettorizzazione e le unità di elaborazione grafica chiamate GPU-SBMM. L'applicazione GPU-SBMM ha prodotto un aumento significativo dell'SNR (da 1±5 dB a 19±5 dB; p<10-10). Inoltre, è stata raggiunta una notevole velocità nel runtime dell'algoritmo (3,56x volte GPU NVIDIA GeForce). In aggiunta, viene presentato un sistema automatico di rilevamento dell'aritmia progettato per produrre la massima precisione diagnostica con una quantità minima di dati utilizzando differential evolution (DE) e una probabilistic neural network (PNN) meno pesante dal punto di vista computazionale. Tutti i test sono stati eseguiti su ECG ambulatoriali e a lungo termine acquisiti utilizzando sensoristica indossabile. Lo schema DE-PNN proposto ha fornito una migliore accuratezza di classificazione considerando 8 classi con solo 41 caratteristiche ottimizzate da un insieme di 253 elementi che hanno causato una riduzione dell'83,7% delle caratteristiche di ampiezza diretta. In conclusione, questo lavoro si è dimostrato utile per migliorare la qualità e l'efficienza del sistema di diagnosi automatica delle malattie cardiovascolari su una piattaforma di monitoraggio della salute cardiovascolare moderna e in evoluzione, ovvero sensori ECG indossabiliAbstract Designing automatic cardiovascular disease (CVD) diagnostic systems specifically for signals acquired using wearable electrocardiogram (ECG) sensors becomes a challenge specifically requiring solutions for signal distortions caused by high level of motion artifacts and efficient CVD diagnosis. Hence the aim of this thesis is to develop an adaptation of Segmented Beat Modulation Method (SBMM, a template-based method for denoising of ECG signals) using wearable ECG data to additionally account for non-sinus rhythms and to increase the usability of modern wearable sensors in comparison to traditional in-clinic machines for CVD diagnosis. SBMM has currently failed to work with abnormal or arrhythmic (rare but critical events often leading to sudden cardiac death) heartbeats which hugely limits its applicability to cardiovascular disease diagnosis in a real-world scenario. To this aim, this work presents Extended Segmented Beat Modulation Method with a heartbeat classification function using convolutional neural network (CNN) that first separates the normal (N) from supraventricular (S) and ventricular (V) heartbeats and secondly uses separate median representative templates to denoise and reconstruct the clean ECG recording. Overall, the CNN classification accuracy (Ac) was 91.5% while the positive predictive (PP) values were 92.8%, 95.6%, and 83.6%, for N, S, and V beat classes, respectively. Eventually, signal-to-noise (SNR) improvement was less than 2 dB in the absence of noise but increased in the presence of noise until exceeding 5 dB in the presence of electrode motion artifacts. Hence, ESBMM proved to be a reliable tool to classify cardiac beats into N, S, and V classes and to denoise ECG tracings characterized by both sinus and non-sinus rhythms maintaining the morphological variability in the pseudo-periodic ECG signal. Other improvements proposed to SBMM are a preliminary compression test using discrete cosine transform. The method is evaluated using SNR and compression ratio (CR) considering varying levels of signal energy in the reconstructed ECG signal. For denoising, an average SNR of 4.56 dB was achieved representing an average overall decline of 1.68 dBs (37.9%) as compared to the uncompressed signal processing while 95% of signal energy is intact and quantized at 6 bits for signal storage (CR=2) compared to the original 12 bits, hence resulting in 50% reduction in storage size. Another improvement dynamic-template SBMM adapts SBMM to heart rate and generates the template in a dynamic fashion every 20 seconds and is particularly targeted and tested for long-term ECG data acquisitions. Another presented improvement adapts SBMM to modern fast hardware using vectorization technique and graphical processing units called GPU-SBMM. GPU-SBMM application yielded a significant increase of SNR (from 1±5 dB to 19±5 dB; p<10E-10). Additionally, a considerable speed up in the algorithm runtime (3.56x on average on an NVIDIA GeForce GPU) was achieved. In a secondary domain, an automated arrhythmia detection system is presented that is designed to produce maximum diagnostic accuracy with minimum amount of data (removing redundant and noisy data) using differential evolution (DE) and a less computationally intense probabilistic neural network (PNN). All tests are performed for ambulatory and long term ECG signals acquired using wearable sensing modality. The proposed DE-PNN scheme provides better classification accuracy considering 8 classes with only 41 features optimized from a 253 element feature set implying an 83.7% reduction in direct amplitude features compared to the other evolutionary and statistical schemes. In conclusion, this work has proved beneficial for improving the quality and efficiency of automatic cardiovascular disease diagnosis system on a modern and evolving cardiovascular health monitoring platform i.e. wearable ECG sensors.
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Klicnar, Lukáš. "Robustní detekce pohybujících se objektů ve videu." Master's thesis, Vysoké učení technické v Brně. Fakulta informačních technologií, 2012. http://www.nusl.cz/ntk/nusl-236535.
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Motion segmentation is an important process for separating moving objects from the background. Common methods usually assume fixed camera, other approaches exist as well, but they are usually very computational intensive. This work presents an approach for scene segmentation to regions with coherent motion, which works faster than similar methods and it is capable of online processing with no prior knowledge of objects or camera. The main assumption is that the points belonging to a single objects are moving together and this applies as well in the opposite direction. The proposed method is based on tracking of feature points and searching for groups with similar motion by using RANSAC-based algorithm. Short-range repair of broken tracks is applied to increase the overall robustness of tracking. Found clusters are subsequently processed to represent separate moving objects.
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Parepalli, Bharath K. "Biomechanical Evaluation of Posterior Dynamic Stabilization Systems in Lumbar Spine." Connect to full text in OhioLINK ETD Center, 2009. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=toledo1262205380.
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Thesis (M.S.)--University of Toledo, 2009.Typescript. "Submitted as partial fulfillment of the requirements for the Master of Science Degree in Mechanical Engineering." "A thesis entitled"--at head of title. Bibliography: leaves 92-98.
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Sandquist, Annie, Kajsa Lindström, and Isabelle Alm. "Nearshoring : motiv och barriärer." Thesis, Högskolan i Borås, Akademin för textil, teknik och ekonomi, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-23456.
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Syftet med denna uppsats är att undersöka vilka motiv samt barriärer svenska klädföretag ser rörande sina sourcing beslut, med fokus på nearshoring och farshoring. Vidare undersöks även hur dessa motiv och barriärer skiljer sig åt beroende på vilket segment klädföretaget inriktar sig på. Västra Götaland har länge varit centrum för textilindustrin i Sverige men har på senare tid konkurrerat med utländska, billigare tillverkningsländer såsom Kina och Bangladesh. Idag har dock en trend uppdagats, då många klädföretag väljer att flytta sin produktion till länder närmare hemmamarknaden, vilket benämns som nearshoring. Uppsatsen har en kvalitativinriktning där en flerfaldig fallstudie med semistrukturerade intervjuer har genomförts med fyra klädföretag baserade i Västra Götaland. Intervjuerna utformades i syfte att undersöka respektive företags motiv samt barriärer för att att arbeta med nearshoring. Det insamlade empiriska materialet analyserades därefter genom indelning av dessa motiv och barriärer i en tabell för att skapa en tydlig överblick. Tabellen analyserades vidare för att hitta mönster och dessa delades sedermera in i sex olika kategorier som lades till grund för analysen. Motiv och barriärer hos de studerade företagen var relativt likartade och överensstämmer med tidigare forskning inom området. De starkaste motiven för nearshoring visade sig vara tid tillmarknaden, hållbarhet och riskhantering medan de starkaste barriärerna var högre kostnader, kapacitet och relation med leverantörer. Motiv och barriärer tenderade även att skilja sig åt beroende på vilket segment inom marknaden ett företag är verksam inom. Sport- och fritidskläder visade sig vara mer fokuserade på kvalitét och pris medan modekedjor är merfokuserade på snabbhet till marknaden.The purpose of this study is to investigate nearshoring motives and barriers in the Swedish clothing industry, and the differences between diverse segments on the market. Västra Götaland, a region in Sweden, has long been the centre for the textile industry in Sweden but has been struggling with competition of foreign, cheaper manufacturing countries like China or Bangladesh. Today, the manufacturing returning to closer areas of the market, labeled as nearshoring, which is shown to be a growing trend. The study has a qualitative research strategy approach where a multiple-case study with semi-structured interviews have been conducted with four clothing companies in Västra Götaland. The interviews were designed to investigate their respective motives and barriers for nearshoring. The collected data was analysed by dividing all of the motives and barriers into a table to get an overview. The table was then analyzed to find patterns. These patterns were later divided into six categories that was used as a foundation for the analysis. The barriers and motives of the different companies are quite similar and complies with the earlier research that has been conducted on the subject. The strongest motives for nearshoring is time to market, sustainability and risk management while the barriers was pointed out as higher costs, capacity and relationship with current partners and manufactures. The motives and barriers tend to shift depending on what segment on the market that the company is operating on. Sport and active wear tend to be more focused on quality and price while fashion companies tend to be more interested in speed to market. This thesis is written in Swedish.
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Brito, da Luz Simao Neto. "Development of a Complete Lower-Limb Subject-Specific MRI-Based Skeletal-Joint Model." Thesis, Griffith University, 2016. http://hdl.handle.net/10072/366521.
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Rigid-body-musculoskeletal models are becoming commonly used to study human motion, particularly of people with some form of neuromusculoskeletal condition. However, these musculoskeletal models are typically generic, having simplified anatomical and kinematic representations, with coarse-meshed bone geometries, and body-segment inertial parameters (BSIP) obtained from a limited number of adult-male cadavers. Furthermore, these models have hip joints that articulate around an estimated hip-joint centre (HJC), two-dimensional-sagittal-plane tibiofemoral (TFJ) and patellofemoral joints (PFJ) models at the knee, and hinges for the talocrural (TCJ) and subtalar (STJ) joints in the ankle and foot. Each person’s model has bone dimensions, BSIPs and joint kinematics that are linearly scaled from the generic models using scale-factors obtained from three-dimensional (3D) positions of motion capture (3DMOCAP) markers or from magnetic resonance images (MRI). However, bone dimensions might not be properly adjusted with linear scaling, which will affect the position and orientation of joint centres and axis, the location of the segments’ centre of mass and moments of inertia, the position of musculotendon length, origins and insertions as well as bone geometry e.g. femur neck-length. Finally, muscle forces, joint angles, moments and internal joint loads of gait estimated using these scaled-generic models have been shown to be inaccurate, probably due to the aforementioned imprecise bone geometries and simplified joint models.Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Allied Health
Griffith Health
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Libiš, Zdeněk. "Sledování objektu ve videosekvencích." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2011. http://www.nusl.cz/ntk/nusl-219351.
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This thesis deals with object tracking in video sequence. It focuses on studying of one object´s motion in static background. Motion is defined by its direction and its speed. It was created 3 operators in RapidMiner to determine it. The operator called AccumulativeDifferenceImage searches a trajectory of motion by technique of accumulative difference image. Operator called OpticalFlow is created to describe type of motion and to find size of location´s transition. The operator called SpeedMeasuing is used for determining of speed, it calculates speed of object by using input´s binary masks in meters by second. In theoretical part of thesis are described the types of segmentation´s methods, basic types of block matching algorithms, attributes of video sequences and problem of recording of motions. In practical part are described implementations of every operator, the testing video sequences and showed results of tests for every operator.
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Kromer, Valérie. "Analyse des forces musculaires au cours de la marche : approche en corps rigide et simulation en mécanismes plans flexibles par éléments finis." Vandoeuvre-les-Nancy, INPL, 1993. http://www.theses.fr/1993INPL040N.
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Ce travail s'inscrit dans le projet européen calies, dont l'objectif est de rétablir la locomotion de patients paraplégiques par stimulation électrique directe de leurs muscles. La première partie porte sur l'analyse et l'évaluation des forces musculaires agissant au cours de la marche normale. Le modèle musculaire retenu est celui de Hill. Les moments aux articulations sont obtenus par une étude dynamique inverse, à partir d'une description cinématique du mouvement. Le problème de synergie musculaire est résolu selon deux méthodes d'optimisation statique, la première consistant à minimiser l'activité musculaire globale, la seconde la fonctionnelle énergie totale. Dans un deuxième temps, la simulation de la marche en corps rigide, pendant la phase oscillante, est réalisée. Elle met en évidence l'instabilité naturelle du genou portant et illustre la nécessité du contrôle de l'extension du genou (contrôle des vastes pour le verrouillage de l'articulation et des ischiojambiers pour l'amortissement du mouvement). Dans une troisième partie, la méthode des éléments finis est appliquée à l'étude du mécanisme flexible constitué des segments squelettiques des extrémités inferieures. Le rôle des masses musculaires est, non seulement de produire le mouvement, mais également de contrôler la déformation élastique du squelette. L'appareil musculosquelettique est optimal en termes de conception mécanique, car il garantit simultanément la sécurité du système et une dépense énergétique minimale
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Havelka, Robert. "Detekce ohně a kouře ve videosekvenci." Master's thesis, Vysoké učení technické v Brně. Fakulta informačních technologií, 2010. http://www.nusl.cz/ntk/nusl-235560.
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This master's thesis deals with fire detection in videosequences. Attention is paid to the known characteristics of fire and basic principles of existing solutions which deal with this issue. The thesis also describes design, implementation and testing of a fire detector that is based on the recognition of suspicious areas by fire color modeling, combined with detection of motion and light intensity variations.
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Pražák, Ondřej. "Lokomoční identifikace osob." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2009. http://www.nusl.cz/ntk/nusl-217769.
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This paper deals with study of human movement and using that in identification. In the first part of my work are explained characteristics of human movement and factors which take effect on these characteristics. Practical part is dealing with design of program which is solving mentioned problems. The input of program is created by video sequence with lateral movement of human. The program is finding coordinates of lower limbs joints. From this coordinates are created locomotion characteristics used for human identification. Matching of time behaviors is based on correlation.
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Shieh, Fang-I., and 謝芳宜. "Studies of Segmental Motion by NMR Relaxation Technique." Thesis, 1997. http://ndltd.ncl.edu.tw/handle/21551051641663911663.
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蘭宜康. "Study of Segmental Motion of Poly (p-Phenylene Vinylene) by Computer Simulation." Thesis, 1997. http://ndltd.ncl.edu.tw/handle/16708600195019658726.
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Ruan, Ya-Li, and 阮雅莉. "Association of neck range of motion and cervical/thoracic segmental mobility with respiratory function in subjects with neck pain." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/51696173202180342595.
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碩士國立陽明大學
物理治療暨輔助科技學系
99
Background: Neck pain is a common problem in the general population. The symptoms often accompany with limitation of cervical range of motion and restriction of mobility. Also, chest pain or difficult to expand chest during breathing has been noted in clinic. It usually results in a frequent source of disability, and has a considerable influence on the quality of life and emotion. However, the connection of neck pain and respiratory are still need to be explored. Purposes: (1) to find out the difference in respiratory function between subjects with neck pain and healthy controls; (2) to investigate the effect of pain characteristics, neck range of motion and cervical/thoracic segmental mobility on respiratory function. Study design: case-control study. Methods: Twenty five patients with neck pain and 26 age-gender matched healthy controls were recruited. Their demography data were recorded. The outcome measures included the characteristics of pain, neck range of motion, cervical/ thoracic segmental mobility, breathing pattern, chest expansion, maximum inspiratory/expiratory pressure (Pimax / Pemax), pulmonary functional test. Differences in all variables between groups were assessed by Independent-t tests. One-way ANOVA was used to analyze respiratory function among different pain duration groups. Pearson correlation coefficient was used to examine the association between neck range of motion, pain severity and respiratory function with the presence of neck pain. Independent t test was used to find out whether the cervical/thoracic segmental mobility to be associated with respiratory function. Results: Patients with neck pain presented increased upper chest mobility during deep breathing, the ratio of chest expansion in deep breathing and resting breathing, and decreased respiratory muscle strength (Pimax and Pemax) (p<0.05). Significant associations were observed between pain severity, the ratio of deep breathing and respiratory muscle strength. Increased pain duration would decrease respiratory muscle strength and increase the ratio of chest expansion in deep breathing. The correlation between neck range of motion and chest expansion was observed. Restricted mobility of lower cervical spine decreased the upper chest expansion in deep breathing; respiratory muscle strength decreased was found when lower thoracic spine restricted (p<0.05). Conclusion: Most of patients with neck pain showed upper chest breathing pattern. Pain severity and duration, neck range of motion, restricted segmental mobility of lower cervical and lower thoracic spine were associated with the change of chest expansion and decrease in respiratory muscles strength of patients with neck pain. Clinical Relevance: The results supported the connection of neck pain and impaired respiratory functions. Clinicians need to notice and examine the impact of respiratory function in neck pain with decreased neck range of motion and restricted cervical/thoracic segmental mobility on patients with chronic neck pain.
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Lin, Chia-Ching, and 林佳慶. "Single- and Two-level Anterior Cervical Decompression and Fusion: Influence of Surgical Type and Morphological Factors on the Total and Segmental Cervical Range of Motion and Kinematics." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/55457963702342387523.
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碩士國立臺灣大學
醫學工程學研究所
102
Objective: To investigate and better understand the influence of Anterior Cervical Discectomy and Fusion surgery on cervical kinematics and to elucidate possible relationships between cervical morphometrics and altered cervical biomechanics. Introduction: Anterior Cervical Decompression and Fusion (ACDF) is one of the most commonly employed surgical techniques to treat Cervical Spondylotic Myelopathy (CSM). Despite the reported high clinical success rates of ACDF, an increased rate of adjacent segment disease (ASD) post ACDF surgery has raised some significant concerns in the literature. Many demographical factors such as gender, age and duration of symptoms have all been implicated to contribute to the development of ASD, however, limited studies have specifically attempted to quantify the relationship between over-compensatory adjacent segmental contribution to total cervical Range of Motion (ROM) and the development of ASD. Given the likely alternation of the cervical biomechanics due to the immobilization of a segment following ACDF, a better understanding of the postoperative kinematical change is well warranted. Moreover, no study has conducted a morphometric analysis of the cervical vertebral column and its influence on the global and segmental ROM in the literature to date. Based on the immanent biomechanical relationship between vertebral morphology and resultant spinal kinematics, a better understanding of the potential influence using an in-vivo, prospective design is needed to fulfill this gap in our knowledge. Materials and methods: Forty-seven patients with clinically diagnosed CSM undergoing either a single- or two-level ACDF were recruited in the study. Neutral, full active flexion and extension lateral radiographs were taken preoperatively and then at 3, 6 and 12 month follow-ups for all patients. Using the obtained radiographs, global ROM of C2-7, ROM of the treated functional spinal unit (FSU) as well as the superior and inferior segmental ROM were obtained using a computer based quantitative measurement analysis software. The relative contribution from the FSU and each of the adjacent segments to total cervical ROM were compared pre- and post-operatively. MRI scans conducted as part of the preoperative workup were also obtained in order to accurately determine the vertebral morphometric measurements, which included vertebral length, vertebral height, and disc height. In order to investigate and simulate the cervical biomechanical properties during the movement, a number of parametric finite element models (FEM) were also constructed based on patients’ radiographs with the observed ROM inputted as the individual loading conditions. Statistically, a mixed design repeated ANOVA analysis was used to determine the interaction and main effects of surgery type (single or two-level) and time (pre-, 3, 6, 12 month). A univariate linear regression analysis was then conducted to determine the relationship between morphological factors and the kinematical changes. Results Overall, 30 single-level and 17 two-level ACDF patients were recruited. The patients consisted of 28 males and 19 females with a mean age of 55.4 (range 30 to 79) years. Single-cage patients demonstrated a significantly decreased total ROM at 3 months (p=0.002) but improved to pre-operative level by 6 months. In contrast, patients with two-cage ACDF demonstrated significantly decreased total ROM at all follow up assessments (p<0.02) and did not reach pre-surgery level even at 12 months post-surgery. Similar trend was observed for the FSU ROM where a significantly decreased contribution was found for the single-cage patients at all follow up assessments (p<0.01), however, the FSU contribution was only significantly decreased at 12 months (p=0.047) for the two-cage patients. In terms of upper adjacent ROM contribution, it was found to be significantly increased at all follow up assessment points (p<0.05) for the single-cage patients but was only significantly increased at 6 months (p=0.042) for the two-cage patients when compared to pre-surgery. However, in terms of the raw contribution, it was noted that the two-cage patients demonstrated a 10-15% more in contribution to the total ROM when compared to the single-cage at the upper adjacent segments. No significant changes were found for both groups for the lower adjacent ROM contribution. For the correlation of morphological factors and cervical kinematical change, in patients with two-cages, the posterior disc height of the FSU’s upper segment was found to have a strong (R=-0.717) and significant (p=0.03) negative correlation with an increased upper adjacent segmental contribution to total ROM. This was not the case for single-cage patients. No other morphological factors were found to have a significant correlation with the post-operative kinematical changes. The FEM modeling illustrated that based on the obtained radiographs, the two-cage patients demonstrated a greater increase in upper adjacent intradiscal pressure (IDP) than the single-cage patients for both flexion (44% vs 20%) and extension (34% vs 23%) respectively. Conclusion: Single-cage patients regained their pre-operative total ROM by 6 months post-surgery and the fused segment demonstrated adequate fusion and immobility by 3 months. The results indicated that the regained total ROM were mostly due to a slight increase in the upper adjacent segment contribution at 3 months, which then remained unchanged throughout the study period. In contrast, due to the increased levels of fusion in the two-cage patients, the fused segment did not demonstrate adequate immobilization until 6 to 12 month post-surgery. Furthermore, patients with two-cages demonstrated a significant increase of upper segment contribution at 6 months and coupled with greater likelihood of an increase in IDP based on the FEM analysis. Lastly but not the least, the upper posterior disc height of the FSU was found to have an association with the increased upper adjacent segment contribution in patients with two-cages.
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Clamp, Melissa Lorraine. "The effects of segmental vibration on hamstring range of motion. A dissertation submitted in partial fulfilment of the requirements for the degree of Master of Osteopathy, Unitec Institute of Technology [i.e. Unitec New Zealand] /." Diss., 2009. http://www.coda.ac.nz/cgi/viewcontent.cgi?article=1013&context=unitec_hs_di.
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Cibulková, Jana. "Segmentace spotřebitelů v cestovním ruchu na základě motivu." Master's thesis, 2013. http://www.nusl.cz/ntk/nusl-167551.
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Liu, Chun-Yi, and 呂俊億. "A Human-like Animation Synthesis System through the Use of 3D Motion Segments." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/us2ybu.
Full textAbstract:
碩士銘傳大學
資訊工程學系碩士班
96
This paper proposes a human-like animation synthesis system that allows the user to author and combine existed 3D motion segments and generates a novel motion sequence. So the user can make different human-like animations without recapturing the motion that is a heavy load. The works of the optical motion capture system adopted in the research is to attach sensors on the body of the actor and to install cameras around the performing space. Then 3D trajectories of sensors are recorded in the C3D format. Due to mistakes of the captured 3D motion raised by the pose and the location of the actor, the system will automatically detect and correct these errors. For exhibiting the performance of the purposed system, we select taekwondo as the experimental target. A taekwondo athlete was employed as an actor to play basic motions and the system captured these motions in C3D files. The user is allowed arbitrary authoring 3D basic motions by using the system interface. The system transforms the direction and the location of the coordinate system and interpolates the trajectory of the sensor in a smooth fashion. The experimental results show synthesized human-like animations with high quality.
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Hong, Guo-En, and 洪國恩. "The Study of Fracture and Failure in the Spinal Motion Segments by Experiments." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/82615038705546925158.
Full textAbstract:
碩士中興大學
機械工程學系所
95
Fracture and failure in the spinal motion segments are studied in this research by experiments. The aim of this study is to discuss the problem of the spinal injuries and the formation processes by the simulation experiments and to investigate the difference between adjacent vertebral bodies after vertebroplasty. In the experiments, we enter the subject in light of vertebral compression fracture and use swinish vertebras as samples. Compression experiments are divided into two stages, single vertebras and three vertebras. In order to simulate the situation of fracture and failure, several chips were cut in the vertebral body. Inside the vertebral body, the different volume of bone cement were injected into the vertebral body to compare with the relatively fit bone cement infusion quantity after experiments. The results showed that vertebroplasty is an effective method in increasing biomechanical strength of vertebral body. According to our experiments, the volume of 4ml~6ml of bone cement can make a near recover in single vertebral body. In the part of three motion segments, infusion of 4ml~5ml of PMMA per specimen provide sufficient strength. Although the volume of bone cement is depend on the fracture and failure in the vertebral body, the result suggest that injecting lower bone cement into the vertebral body during the vertebroplasty.
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Joeng, Yung-jyi, and 熊永吉. "Coordination of Body Segments for the Motion Control a Biomimetic Autonomous Underwater Vehicle." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/13023797303874360925.
Full textAbstract:
碩士國立臺灣大學
造船及海洋工程學研究所
90
Autonomous underwater vehicles (AUVs) have applications in many undersea missions. They are powered by rotary propellers driven by electric motors. But the low efficiency of the small diameter propellers coupled with the large fraction of the hull volume induced positioning, turning and hovering problems. Recently, the development of biomimetic AUVs (BAUVs) is in progress to overcome the problems of traditional AUVs. A dynamic model of BAUVs being developed at the NTU is presented. This allows us to simulate the dynamic behavior of the BAUVs. We develop a local control law which coordinates joint angles by the use of the position of the center-of-mass in the local coordinate frame. Here we introduce three parameters to define the position of the center-of-mass, and find their effects on the global performance by computer simulations. According to these properties, we then develop the global control law for the navigation problem. The major contribution of this thesis is the development of a coordinated motion control law for BAUVs. We use three parameters to coordinate the joint angles. And we develop a guidance and control method to control the BAUV under model uncertainties and under external disturbances.
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Ndebele, Bright Bekithemba. "The diffraction, reflection and propagation of cylindrical shock wave segments." Thesis, 2017. http://hdl.handle.net/10539/23544.
Full textAbstract:
A thesis submitted to the Faculty of Engineering and the Built Environment, University of
the Witwatersrand, Johannesburg, in ful lment of the requirements for the degree of Doctor
of Philosophy.
Johannesburg, May 2017Shock{waves (shocks) exist in various shapes; restricted to two dimensions some examples are planar, cylindrical, parabolic and elliptical. However, most shock{wave research has been focussed mostly on plane shocks. In this research, the scope is expanded to cylindrical shock{wave segments where a plane shock can be viewed as a cylindrical shock segment (referred to as a cylindrical shock) with a large radius of curvature; with this view, the expectations are that cylindrical and plane shocks behave similarly although with quantitative di erences. Whereas plane shocks have constant orientation, constant strength and can be imagined to extend unbounded, cylindrical shock segments demand that both ends be bound; this leads to spatial constraints, shock strength varying with respect to radius and shock orientation being non-constant. Three shock phenomena were investigated: di raction, re ection and propagation in converging diverging nozzles. Shock{tube experiments were run for shocks with a radius of 165 mm and strength between Mach numbers 1.2 and 1.7. Complementing these were Computational Fluid Dynamics (CFD) and Geometric Shock Dynamics (GSD) simulations where GSD relies on Whitham's equations. On shock di raction, cylindrical shocks were shown to behave qualitatively like plane shocks. Upon encountering a sharp corner, expansion waves propagate along the shock. However, after re ecting o the opposite wall they become compression waves and form a 'Mach re ection (MR)' like con guration on the shock front. A method for calculating the locus of the expansion waves based on Whitham's theory is presented, which on comparison with CFD simulations gives good correlation. Comparisons of shock pro les calculated using Whitham's theory and CFD is also made; it showed good correspondence before the formation of MR like con gurations after which the pro les di er. The re ection of cylindrical shocks was investigated from both an experimental and numerical perspective. Shock{tube experiments were run for shocks propagating on concave cylindrical walls with radii of 100 mm, 180 mm, 140 mm and 82 mm, the range was expanded by use of CFD. An expression for calculating the locus of the MR that forms on iii the shock front was derived which generalises onto plane shocks. Two limits were recognised, one where shock radius is much greater than wall radius and another where shock radius is much smaller. The former corresponds to a cylindrical shock on a plane wall while the latter a plane shock on a cylindrical wall as illustrated by the data gathered. Cylindrical shock propagation in converging-diverging nozzles was also investigated. In this case, the phenomena at play are di raction, re ection and focusing, a combination which results in a complex evolution of the shock front. Two types of channels were investigated, one formed from a 3rd order polynomial and another from circular arcs. In both cases, wall signal were generated on either side of the shock which split the shock{front into three sections. The decreasing channel cross{section area causes the shock strength to increase resulting in very weak MR formation on the shock front. Channels from circular walls exhibit a single peak in the centre line shock strength while that from polynomial pro le walls results in a double peak. This was then related to type of wall disturbance generated.
MT 2017
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Chen, Yu-Chih, and 陳昱志. "The Study and Application of Multi-Segment Contouring Curves for Precision 3D Motion Platform." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/ftshbq.
Full textAbstract:
碩士國立臺北科技大學
自動化科技研究所
98
In CNC machining, the execution of a complex profile is usually composed of many sequential simple curve segments, so the table has to accelerate and decelerate in each segment. However, the frequently speed change not only extend the running time but also make the machining quality not uniform. Besides, the improper force and vibration caused by improper speed planning would shorten the life of machine center. This study investigates the phenomenon and problems of multi-segment motion with single speed planning, then proposes a method to compensate. The C-843 motion control card and the X-Y-Z platform model M511.DD, which are both produced by Physik Instrument Inc., are used for experiment in this research. The experiment result shows that when two curve motions connect with a non-zero speed, the proposed compensation method could effectively reduce the uncertain speed error caused by the residue of interpolator.
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Chau, Wing-Sze, and 周詠詩. "Key Motion Segment Spotting by Automatic Grouping and Time Warping Based on Dynamic Programming." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/4p5kat.
Full textAbstract:
碩士國立東華大學
資訊工程學系
102
This paper presents the design of a Key Motion Spotting (KMS) system which allows a user to input a query sequence of motion, called the key motion, and then locates all occurrences of the subsequences similar to the key motion within long motion sequences. Differing from the conventional retrieval systems of motion sequences, which simply evaluate and rank the similarity between the queried key motion and every database sequence computed from the whole-sequence matching, our system must locate within each database sequence the exact end points where the subsequences similar to the key motion may start and stop. To this end, we propose in this thesis an efficient and effective End Point Detection (EPD) method by extending the Dynamic Time Warping (DTW) algorithm. To enhance the robustness of the EPD method, we further devise a difference reinforcement method in the DTW so that the end points can be detected more tangibly. When matching a key motion with a database sequence, the KMS system might get poor result due to the variations of motion speed in the sequences. To tackle the problem, an automatic frame grouping method is proposed to autonomously condense the queried key motion by grouping the consecutive frames of no noticeable movements into a cluster which is then replaced with a single representative frame. The result of the key motion condensing is then used to guide the condensing of each database sequence so that both the key motion and the database sequence can have better consistency in motion speed. To evaluate the performance of the proposed methods for the KMS system, we implement the system to test a database of 3-D motion sequences acquired from the Microsoft Kinect. Different features are also defined to characterize the sequence of body motion. Several experiments are conducted to examine the effects of various methods, as well as features, proposed in the KMS system. The results show that the proposed methods are efficacious in tackling the target problems. Besides, the achieved performance, in terms of the precision rate and the recall rate, is superior to that of an existing method called the Subsequence DTW (SDTW) algorithm. In particular, our method is far better than the SDTW in dealing with the variations of motion speed owing to the incorporation of the proposed automatic frame grouping mechanism.
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AlaviMehr, J. "The influence of ride control systems on the motion and load response of a hydroelastic segmented catamaran model." Thesis, 2016. https://eprints.utas.edu.au/23405/1/AlaviMehr_whole_thesis.pdf.
Full textAbstract:
The operation of high-speed catamarans in large waves can produce significant vessel motions that can lead to passenger discomfort as well as extreme loadings during full bow immersion and wave slam impact. This not only can generate large bending loads on the hull structure but also has significant effects on the fatigue life of the vessel. These large loads and motions can be effectively reduced through the implementation of a Ride Control System (RCS) that can significantly reduce the extreme loads sustained by the hull girder and reduce the incidence of motion sickness for passengers on-board the vessel. Although ride control systems have been implemented on full-scale catamaran vessels, the parameters that influence the response have not been previously quantified partly due to the limitations of testing at full-scale. To accurately investigate these parameters it is needed to undergo testing in controlled conditions and to this end a 2.5 m scaled catamaran model has been developed with an active ride control system based on the 112 m INCAT catamaran to investigate the system parameters influencing the response of the vessel. The 2.5 m hydroelastic segmented catamaran model was set-up with an active T-Foil and stern tab ride control system specifically for towing tank testing at the Australian Maritime College (AMC) to determine the motions and loads response in headseas. Step and frequency responses of the ride control system were first investigated by calm water open-loop tests to determine the control gains needed for closed-loop active control tests. Appropriate combinations of the control surface deflections were then determined to produce pure heave and pure pitch response forming the basis for setting the gains of the ride control system to implement different control algorithms in terms of the heave and pitch motions in encountered waves. Two hydrostatic methods were applied to predict the T-Foil and stern tab responses based on a static load experiment and a hydrostatic prediction and there was close agreement between the two outcomes. This was extended by a dynamic prediction of the response of the moving model based on a two degree of freedom rigid body analysis using strip theory. A series of model tests in head seas at different wave heights and frequencies was then undertaken at the AMC towing tank for different ride control conditions including without RCS, passive RCS and active RCS to measure the heave and pitch motions as well as the centre bow slam force and the demihull slam induced bending moments. Three different ride control algorithms of heave control, local control and pitch control were developed to activate the model scale ride control surfaces in a closed loop control system configuration. The response amplitude operators (RAOs) as well as the response phase operators (RPOs) of the model were evaluated from the heave and pitch data. In addition to the RAOs and RPOs, the amplitude and phase of control surfaces were analysed in order to present the range of control surface deflection as well as the phase lag between the control surfaces deflection and the model motions. Comparing the results of the model without RCS with the results of the model with a passive RCS it was found that the deployment of the T-Foil to a fixed position and acting as a passive control surface reduces the peak heave and pitch motions. As expected heave and pitch were more strongly reduced by their respective control algorithms. This was more evident in the pitch control mode where it significantly reduced the pitch RAO. The centre bow slam force and the demihull slam induced bending moments were also significantly reduced by implementing the pitch control mode. The motion and load results obtained through this unique and comprehensive investigation of a catamaran model fitted with the model scale ride control system have clearly demonstrated the positive effects of using improved ride control algorithms on the vessel motions and loads response. This consequently has a direct impact on the design of future catamaran vessels allowing ship designers to optimise the structural design of the vessel whilst improving passenger comfort and reducing the incidence of motion sickness in particular when operating in larger waves.
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Matsubara, S. "Ship motions and wave-induced loads on high speed catamarans." Thesis, 2011. https://eprints.utas.edu.au/11843/1/Matsubara_whole_thesis.pdf.
Full textAbstract:
Advancement in the design of large high-speed ferries demands comprehensive knowledge of ship motions and wave-induced loads to optimise their structural integrity. This investigation focused on the fluid structure-interaction problem experimentally to obtain such information.
Motions and loads were investigated by using two different high-speed catamaran models and a full scale ship. Firstly, a hydroelastic segmented model (HSM) of the INCAT 112 m class wavepiercer catamaran with centrebow was designed. It was tested in a towing tank for a range of head seas conditions to determine the motion responses, vertical bending moment (VBM) and slam loads. A second catamaran model was designed and tested in oblique seas in a model test basin (MTB) to examine the motions and asymmetric wave-induced loads. Thirdly, full scale measurements were performed during the delivery voyage of the INCAT 112 m Hull 064 from Hobart in Australia to Hakodate in Japan, to measure the motions and structural load responses.
The structural dynamic behaviour of the full scale vessel was replicated by the HSM model and the slamming and subsequent whipping behaviour were successfully modelled. As wave energy was consumed in the structural vibration of the model, the heave and pitch transfer function peaks reduced significantly when compared to the rigid configuration. The HSM test results also showed a strong non-linear motion response, with respect to wave height for this type of vessel, mainly due to the influence of the centrebow. The peak values for the VBM and slam loads were confirmed to be proportional to the square of the wave height for large waves. The MTB test model, which was not fitted with a centrebow, provided linear pitch, heave and roll motions for varying wave heights. The pitch connecting moment was found to be the dominant of the asymmetric wave loads and was linear with respect to wave height. During the full scale measurement programme, slamming phenomena were clearly recorded whilst crossing the Bass Strait. A reconstruction of the event, from the measured data, indicated that a slam event with subsequent whipping occurred with a bow down trim. Spectral analysis was used to detect the response frequencies of the VBM and machinery, with the frequency of the longitudinal mode increasing as the displacement reduced.
These experimental programmes, encompassing model and full scale measurements, have revealed valuable insights into the motion and structural dynamic behaviour of large high-speed catamarans. A comprehensive set of motion transfer functions, VBM and slam loads coefficients have been obtained, thus providing designers with important slam and wave load knowledge to aid the improved structural optimisation of these vessels.
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Chin, Yung-Chin, and 金永欽. "The bone strain of vertebral body and global force response of motion segment during sagittal eccentric vertical loading." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/51966569395691814953.
Full textAbstract:
碩士國立臺灣大學
醫學工程學研究所
93
Abstract Study Design.Three standard materials and porcine cervical two-motion segments are used to investigate the mechanical reaction and strain field response to the same loading condition. The effects of material characteristics on subjects’ mechanical performance are also discussed. Background.Because spinal injuries are frequently resulted by enormous dynamic loading, we intend to simulate the strain distribution of anterior lumbar vertebral bodies and their mechanical behaviors under different impact loading. Objective.To investigate the mechanical behavior of spinal motion segments and distribution of strain field of anterior vertebral bodies while they are subjected to impact loading. Method.13 porcine cervical two-motion segments were used. C3-5 (n=7) and C6-T1 (n=6) were dissected from them. Three standard cylinders made of AL, PE and PU, respectively, were used as reference samples. All specimens were applied with axial distributive load and point compressive load with different loading energy and contact period. Surface strains were measured with a three-axis strain gauges rosette attached to the anterior wall of the middle vertebral bodies. The mechanical behaviors of all samples were also analyzed. Result.Under distributive loading, the principle strain increases as the loading energy rises. Under point loading, the maximum principle strain occurs when the specimens are loaded at anterior and posterior points, respectively, while the strain is minimal when the specimens are loaded at the 7th point. For the specimens of larger stiffness, the axial resultant force remains constant despite the loading location changes. But the horizontal resultant force and sagittal resultant moment show opposite trend. Their directions are the same as expected. However, for the specimens of smaller stiffness, the axial resultant force, the horizontal resultant force and sagittal moment decline with the change of loading location, while the directions of the last two are different from the theoretical results.
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Lai, Cheng-Chuan, and 賴政全. "Gross Force and Moment Responses of Spine Motion Segment During Cyclic Loading and Facet Joint Contact Force During Impact Loading." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/10718316661552377805.
Full textAbstract:
碩士國立成功大學
醫學工程研究所碩博士班
92
Finding the spinal motion segment under repetitive activities and the facet joint load sharing of spinal motion segment under compressive impact loading are an important spine biomechanics subjects. We also believed that two factors have been associated with low back pain (LBP). The cyclic loading causes a decline in the stiffness properties of the motion segments and predisposes them to more risk of buckling injury. The facet joint plays an important role in load sharing of spinal motion segment. Nevertheless, to the best of authors’ knowledge, no body up to data gives quantitative ideas of the mechanical interaction within the spine, and no body is able to detect the force history of facet joint under impact loading. The current study developed a unique apparatus using an in vitro porcine lumbar spine model to quantify the gross force and moment response of spine motion segment during cyclic loading and facet joint contact force during impact loading In cyclic loading, eight fresh-frozen porcine spine joint (L3/L4) was used in the experiment. A “drop-tower type” impact testing apparatus was modified for the testing. The energy was transmitted to the specimen through the impounder. The specimen was loaded at two postures; i.e., the distributed and anterior point-load posture. The loading was set at 200 N compression and 100 N tension. The loading time is five hours; hence 90,000 cycles in total were applied. We record half second data every 5 minutes. Sixty sets of data were collect through the loading history. Signals of input force, three dimensional reaction forces and moments from the six-axial force load cell were all recorded at 10 kHz sampling frequency. In impact loading, the pressure sensors were inserted into the both facet joints to find the joint contact force. The 1.2J impact energy was transmitted to the specimen through the impounder. The specimen was loaded at seven points from anterior to posterior. Signals of facet joint contact force, input force, three dimensional reaction forces and moments from the six-axial force load cell were all recorded at 10 kHz sampling frequency. We found that the axial force responses between two loading conditions are similar. The anteroposterior and lateral shear force are slightly higher at point-loaded loading condition. However, the bending moment responses is very different between the two loading posture. The peak to peak magnitude of bending moment reaches 3 Nm during distributed loading, but reaches 11 Nm during anterior pointed loading. the cyclic creep deformation curve showed that the spine joint had not reached the steady state after 5 hours, i.e., 90,000 cycles of loading. In impact loading, the moment is in flexion when the load was applied at the anterior of vertebral body, and is in extension when the load is applied at central and posterior vertebral body . The facet joint force remained constant when the loading was applied anteriorly, but responed quite promptly when the loading was applied posteriorly. The facet joint shared 13% and 28% of axial loading when the load is applied anteriorly and posteriorly. The extension moment increased as the loading point moves posteriorly . We successfully developed an apparatus that is able to give force controlled cyclic loading at very low price. The testing apparatus is able to detect the three dimension forces and moments responses of testing specimens and that is able to detect the force history of facet joint.
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Vávrová, Lucie. "Turistický produkt formou služby v informačních centrech." Master's thesis, 2019. http://www.nusl.cz/ntk/nusl-428861.
Full textAbstract:
The aim of this diploma thesis is suggesting suggestions of development of tourist products on tourist information centers in the Czech Republic. In the part Library Review are described the expert knowledge of the issues covered by diploma thesis. In the part Own work, there is summary of the most interesting research in the tourism, the results of quantitative research, the segmentation of visitors to the tourist information center, the results of qualitative research and the suggestions of development of tourist products.
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Shabani, B. "The effects of tunnel height and centre bow length on motions and slam loads in large wave piercing catamarans." Thesis, 2017. https://eprints.utas.edu.au/23923/1/Shabani_whole_thesis.pdf.
Full textAbstract:
An above water centre bow in wave piercing catamarans provides additional reserve buoyancy for minimising deck diving in following seas. The centre bow entry in waves, however, contributes to the severity of the wet-deck arch slam loads and slam induced bending moments. In this thesis, the effects of the centre bow length and wet-deck height/tunnel clearance on the motions and slam loads in large wave piercing catamarans are investigated through model tests to establish a framework for the preliminary design analysis.
The model tests were performed in regular waves in head seas using a 2.5 m hydroelastic segmented catamaran model designed with an adjustable wet-deck and a changeable centre bow segment. Five different centre bow and wet-deck configurations were considered and over 500 towing tests were performed at two model speeds, in three wave heights and for various wave encounter frequencies. The catamaran model was comprehensively instrumented to measure the pitch and heave, centre bow loads, centre bow accelerations, wet-deck arch slam pressures and the vertical bending moments at two segment cuts located in each port and starboard demihull.
Motion analyses showed that both heave and pitch increased over a wide range of encounter wave frequency as the wet-deck height of the catamaran model increased. Increasing the length of the centre bow showed an increase in the pitch but a decrease in the heave for a particular range of encounter wave frequency. The vertical motions along the model length indicated that the position of minimum vertical displacements and accelerations were aft of the LCG, between 20% and 38% of the overall length from the transom. The increase in wet-deck and consequently the archways clearance also resulted in an increase in relative vertical displacement in the centre bow area. This indicated that although the wet deck height had been increased, the consequent increase in motion still caused slamming to occur.
In dynamic analyses, the maximum force acting on the centre bow segment during a slam event was decomposed into a bow entry force and a slam force. It was found that the slamming force, the centre bow entry force and slam induced bending moment increase as the centre bow length increases. Increasing the wet-deck height reduced the maximum slam load and pressure in moderate waves, but not in large waves. A correlation analysis between the slam force and slam pressure showed that the slam loads increase in the longer centre bows because of the increase in the impact area. The location of maximum pressures along the centre bow length was more related to the encounter wave frequency rather than the centre bow configurations. The distribution of the peak pressures within the centre bow archways showed that the inboard peak pressures were higher than the top arch and outboard peak pressures.
The slam occurrence and severity for different centre bow and wet-deck configurations were analysed by considering the centre bow immersion depth and relative velocity at slam using the undisturbed water profile. It was found that the undisturbed immersion depth for severe slam loads was greater than the immersion depth at the wet-deck level. Therefore, the cross structure between the demihulls and the centre bow can be modified to reduce the slamming pressure.
The results obtained by the comparison of the various centre bow and wet-deck configurations demonstrate the significance of considering the effect of the centre bow and archway slamming in structural design and suggest that the class rules currently available for wave piercing catamarans with a flat deck structure could be modified accordingly. Amongst the tested centre bow configurations, the shortest centre bow was the best design for slam load alleviation. Ideally, a trade-off amongst the centre bow buoyancy in waves, slam load and the catamaran motions should be made to optimise the centre bow design according to the vessel‟s operating conditions.
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Hsu, Jung Mu, and 許榮木. "Study on the Molecular Motions of the Segmented Polyurethane Elastomers based on TDI with the Effect of NCO Content on the Thermal Transitions." Thesis, 1999. http://ndltd.ncl.edu.tw/handle/04306870603834532536.
Full textAbstract:
博士國立臺灣科技大學
化學工程系
87
Segmented polyurethanes based on toluene diisocyanate (TDI) are made by a two-component system, which consists of a TDI-prepolymer and an aromatic hardener such as the methylene-bis-orthochloroaniline (MOCA). The prepolymer that contains the soft segment is the essential part in polyurethane that determines the elasticity. Most often the soft segment used in the preparation of prepolymer is the poly (propylene glycols) (PPG) that constitutes a wide distribution with a repeating unit of -CH(CH3)CH2O-. This system provides a convenient method for making a variety of polyurethanes from soft elastics to tough and hard materials with variations, either by the composition or by a structural alternation of the soft segment, such as with poly (tetramethylene oxide), polycaprolactone, and/or by the copolymers of polymethylphenylsilox-ane and phosphonate or phosphate, among others. Consequently, the segmented polyurethane with variations in the widely distributed soft aliphatic chains, and the hard aromatic TDI-MOCA segment in the backbone, is often observed with a broadened glass transition (Tg), appeared in the differential scanning calorimeter (DSC) thermogram. Thermal analyzers such as thermal mechanical analyzer (TMA) and dynamic mechanical analyzer (DMA) are also being used for the measurements of the Tg data. Schneider and Paik Sung used thermal analyzers in their studies of hydrogen bonding in polyurethanes in association with data measured by the infrared spectroscopy, and by the small angle X-ray scattering (SAXS). They concluded that a high degree of hard-soft segmental mixing occurred in the TDI-based polyurethanes. This mixing phenomenon of the hard-soft segment was also reported by Koberstein and Stein in their studies with the SAXS in the TDI-ethylene glycol system. One characteristic property of the well-mixed hard-soft segment in polyurethane is the transparent appearance. The other is the excellent elasticity often observed in TDI-based polyurethanes. Thermal characteristics of the polyurethanes are often indicated by the Tg transition and are measured with thermal analyzers. For example, the difference of the TDI-based to the related segmented polyurethanes of the methylene diphenyl diisocyanate (MDI)-butanediol system can be made with the measurement at their Tg transitions by a thermal analyzer such as DSC. The DSC spectrum of the MDI-based polyurethane shows the endothermic peak after the Tg transition indicating the separated hard and soft domains in the morphology. Whereas, the 2,4-TDI-based polyurethane shows only the Tg transition, indicating the well-mixing of the soft and hard segment. Thermal analyzers of DMA and TMA also provided useful information. The recent innovated thermally stimulated current (TSC) technique provides more sensitive observations on the local and the molecular relaxations of the polymeric materials. Most of the relaxation transitions occurred in the temperature range from -150 to 200 oC including sub-Tg and Tg transitions. They could be observed with a simple sample preparation in the TSC measurement. This technique has been used in the measuring of Tg transitions of a variety of thermal plastics such as the observation on the multiple relaxation transitions in polystyrenes (PS) that were then attributed to the thermal history for these transitions. The versatility of the TSC depolarization has been illustrated in the measurements of Tg transitions of the amorphous thermoplastics. Ranging from single-componented macromolecules and copolymers to the blends. Segmented polyurethane is a copolymer with a long and soft aliphatic segment like PPG, PTMO, PCL and a hard segment of the combined TDI and MOCA aromatic moieties. The localized motions of the segments, or the cooperative motion of the soft segment in association with the molecular backbone, can be measured by the depolarization relaxation technique as long as these transitions occurred in amorphous phase. The study on thermal characteristics of Tg transition of the polyurethanes is therefore most suitable with TSC technique with the relaxation mapping analysis (RMA) for additional verification on the Tg assignment. Thermal relaxation transitions of TDI-based polyurethanes (PU) were characterized by the TSC technique with verification data from the RMA measurement. TDI-based PU elastomers with PPG, PTMO and PCL as the soft segment and MOCA as the hardener, showed three relaxation transitions. They are accordingly:- (1) a sub-Tg transition of the terminal groups occurred near -135 oC (assigned as transition), (2) the Tg transition (assigned as transition), and (3) a global transition occurred above the Tg transition (assigned as Tglobal transition). Another transition was defined as ■ transition due to its temporary behavior. As expected, the temperature of Tg transition of the polyurethane was related to the chain length, and is attributed by the motion of an soft segment dominated urethanic chain. Also, it may be associated in the cooperative movement with the hard segment. The Tglobal transition appeared above the Tg was identified and attributed to the global transition in the macromolecule scale. Furthermore, was supported by the tangent plot of the DMA measurement. The TSC measurement on thermal characteristic transitions of TDI-based polyurethane provided a whole range of thermal transitions including a sub-Tg transition, the Tg transition (observed by DSC), and global transition (observed by DMA) with sample preparation in one single measurement being of relative ease. The aims of this investigation were to characterize the thermal relaxation transitions occurred in the Tg region of the TDI-based polyurethanes by the TSC technique, and with the thermokinetic data from the RMA for the verification of the Tg transition. The resulting TSC data may provide much clearer data for the understanding of the nature of the transitions in comparison with similar data from the DSC and the DMA measurements. Thermal transitions of the TDI-based polyurethane elastomers with PPG-1000, PTMO-1000 and PCL-1000 as the soft segment with variations of NCO content were characterized by the depolarization technique in TSC with the thermal windowing technique on the selected specimens in the RMA measurements. Results indicate that the broaden thermal transition in the glass transition region as observed in DSC thermogram is related to combined Tg transition and the Tglobal transition in the TSC spectrum. This Tglobal transition is in association with the macromolecular property as detected by the tangent in the DMA measurement. The increase in the Tg with the high NCO content may be due to the structural modification on the urethanic chain with the additional linkage of the hard segment that affected the cooperative motion of the molecular chain. Data measured from DSC, TSC/RMA and DMA with the simulated DEA and the wide angle X-ray data are presented for the characterization of the polyurethanes. The RMA measurement leads to the compensation search on the Tg transition, and provides pertinent thermokinetic data that correlates the NCO content with the changes in both enthalpy and entropy of the relaxation behaviors in the Tg transition of the polyurethane elastomers. This widen Tg transition was further analyzed by thermal windowing technique of RMA. Increases in the following Tg temperature ranges of 25 oC (-50 to -25 oC), 50 oC (-50 to 0 oC), 55 oC (-50 to 5 oC), and 60 oC (-50 to 10 oC) for PU-PPG-1000 specimens in 4%, 8%, 10% and 12% NCO contents were detected in the RMA spectra. The compensation parameters (Tc, log ■c of polyurethane specimens in order of NCO content are (10.1, -2.85); (39.6, -3.08), (51.8, -3.71) and (85.8, -4.49) for PU-PPG-1000 specimens in 4%, 8%, 10% and 12% NCO contents, respectively. In this study, the liquefied curative was also investigated for practical commercial need. A liquefied curative in MOCA/DOP was used as the substitute curative for the hot-melt MOCA curative in a two-component preparative system for the TDI-based polyurethane elastomers. The polyurethane elastomer specimens based on this liquefied curative were prepared with three different soft segments with the addition of various plasticizers. The DOP-added specimens were evaluated by the depolarization technique in the TSC/RMA. The results were also compared with DSC and DMA on the observation on the changes in thermal transitions. Results indicated that at low DOP content of less than and including 26 wt% were that little disruption on the urethanic matrix in the TDI-PCL/MOCA-DOP system. However, at 47 wt% DOP content, a disruption in TDI-PTMO amorphous phase by DOP was observed. The optimum weight ratio of MOCA/DOP was found to be 1:2, and the liquefied solution stabilized at ambient temperature. Also, it may be applicable for use as an ambient curative of the preparation of the TDI-based polyurethane elastomers at low temperatures.
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Baspinar, Ebru-Eylem. "Le rôle du motif hydrophobe VAVIM situé au niveau de IVS6 dans les mécanismes d'activation et d'inactivation du canal calcique Caᵥ2.3." Thèse, 2006. http://hdl.handle.net/1866/15774.
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