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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Muskelstyrka hos individer med femoroacetabular impingement – en systematisk översikt

Gillsell, Simon January 2019 (has links)
Bakgrund Så kallat femoroacetabular impingement (FAI) är en överbelastningsskada som är vanligare hos idrottande individer jämfört med icke idrottande individer. Huruvida individer diagnosticerade med FAI enligt riktlinjerna från The Warwick agreement uppvisar lägre muskulär styrka jämfört med kontralateral sida eller kontrollgrupp är i dagsläget inte utforskat. Syfte Syftet med den här studien är att klargöra huruvida individer med FAI uppvisar lägre muskulär styrka eller inte. Metod En systematisk review i enlighet med PRISMA-guidelines genomfördes. Studier som undersökt muskelstyrka med antingen handhållen dynamometer eller motordriven dynamometer och uppfyllde inklusionskriterierna inkluderades. Kvalitén på studierna och den samlade evidensen bedömdes utifrån GRADE-systemet. Resultat Detta arbete inkluderar sex studier och visar att individer med FAI uppvisar lägre isometrisk höftstyrka i samtliga rörelseriktningar för höftleden jämfört med kontrollgrupp. Inom individer med FAI är den affekterade sidan svagare vid isometrisk höftstyrka i flexion, extension, adduktion och inåtrotation. Avseende isokinetisk höftstyrka är individer med FAI svagare i koncentrisk/excentrisk flexion, koncentrisk/excentrisk extension, inåtrotation och utåtrotation jämfört med kontrollgrupp. Inom individer med FAI är den affekterade sidan svagare vid isokinetisk höftstyrka i koncentrisk/excentrisk flexion och i koncentrisk extension, men starkare i excentrisk extension. Konklusion Individer med FAI uppvisar lägre höftstyrka jämfört med asymtomatisk kontralateralsida och med kontrollgrupp både vid isometriska och isokinetiska mätningar av höftstyrka. Graden av patofysiologi och ålder på forskningspersonerna påverkar resultatet vid mätning av muskelstyrka inom denna population.
2

Responsabilité civile et neutralité de l'internet. Essai de conciliation / Civil liability and net neutrality. Conciliation proposal

Tourette, Alexandre 07 December 2015 (has links)
Il est bien connu que la responsabilité civile appliquée aux intermédiaires techniques de l’internet gouverne bien au-delà de ses destinataires directs. Par le biais de sa fonction normative, elle peut inciter les fournisseurs d’accès et les hébergeurs à restreindre la liberté des utilisateurs du réseau. Pour cette raison, la loi a limité leur responsabilité dès le début des années 2000. Alors que le régime de responsabilité qui en découle est régulièrement au cœur de l’actualité juridique, la neutralité de l’internet fait aujourd’hui l’objet de toutes les attentions. Ce concept émergeant est présenté, tour à tour, comme la condition de la liberté sur le réseau et comme le complice des pires excès. À l’heure où sa consécration légale est proposée avec insistance, il apparaît indispensable de s’enquérir de ses interactions avec une responsabilité civile qui s’inscrit, depuis les origines, au cœur du « droit de l’internet ». La présente recherche illustre, qu’au-delà d’une opposition apparente, les deux concepts peuvent s’enrichir l’un l’autre, pour peu que l’on en fasse une lecture raisonnable. Dans cette optique, les limitations de responsabilité dont bénéficient les intermédiaires techniques épousent les contours de la neutralité. La responsabilité civile appliquée à l’internet s’en trouve éclairée d’un nouveau jour. En retour, la neutralité acquiert une considération pour les dommages qu’elle cause. Elle y gagne un caractère raisonnable qui lui était, jusqu’ici, inconnu. L’espoir est alors permis que, loin du concept destructeur parfois dénoncé, la neutralité de l’internet contribue à équilibrer les relations tumultueuses entre libertés et responsabilité sur le réseau. / It is widely known that the civil liability applied to internet intermediaries governs well beyond its direct recipients. Through its normative function, it can encourage hosters and internet service providers to restrict freedom of network users. For this reason, the law limited their liability in the early 2000s. While this system of liability is regularly at the heart of legal news, the net neutrality is now the subject of all attention. This emerging concept is presented, alternately, as the condition of freedom on the network and as an accomplice of the worst excesses. At the time when its legal consecration is suggested with insistence, it is essential to inquire about its interactions with civil liability recorded at the heart of the "internet law". This study demonstrates that, beyond an apparent opposition, the two concepts can be enriched each other, as long as we make a reasonable reading. In this context, the limitations of liability of the technical intermediaries are close to fit with neutrality. It sheds a new light on the civil liability applied to the internet. In return, neutrality becomes a consideration for the damage it causes. It earns a reasonable characteristic that was unknown so far. Far from a destructive concept often denounced, we can hope that the neutrality of the internet helps balance the tumultuous relationship between freedom and responsibility in the network.
3

3D Segmentation of Cam-Type Pathological Femurs with Morphological Snakes

Telles O'Neill, Gabriel 30 June 2011 (has links)
We introduce a new way to accurately segment the 3D femur from pelvic CT scans. The femur is a difficult target for segmentation due to its proximity to the acetabulum, irregular shape and the varying thickness of its hardened outer shell. Atypical bone morphologies, such as the ones present in hips suffering from Femoral Acetabular Impingements (FAIs) can also provide additional challenges to segmentation. We overcome these difficulties by (a) dividing the femur into the femur head and body regions (b) analysis of the femur-head and neighbouring acetabulum’s composition (c) segmentations with two levels of detail – rough and fine contours. Segmentations of the CT volume are performed iteratively, on a slice-by-slice basis and contours are extracted using the morphological snake algorithm. Our methodology was designed to require little initialization from the user and to deftly handle the large variation in femur shapes, most notably from deformations attributed to cam-type FAIs. Our efforts are to provide physicians with a new tool that creates patient-specific and high-quality 3D femur models while requiring much less time and effort. We tested our methodology on a database of 20 CT volumes acquired at the Ottawa General Hospital during a study into FAIs. We selected 6 CT scans from the database, for a total of 12 femurs, considering wide inter-patient variations. Of the 6 patients, 4 had unilateral cam-type FAIs, 1 had a bilateral cam-type FAI and the last was from a control group. The femurs segmented with our method achieved an average volume overlap error of 2.71 ± 0.44% and an average symmetric surface distance of 0.28 ± 0.04 mm compared against the same, manually segmented femurs. These results are better than all comparable literature and accurate enough to be used to in the creation of patient-specific 3D models.
4

3D Segmentation of Cam-Type Pathological Femurs with Morphological Snakes

Telles O'Neill, Gabriel 30 June 2011 (has links)
We introduce a new way to accurately segment the 3D femur from pelvic CT scans. The femur is a difficult target for segmentation due to its proximity to the acetabulum, irregular shape and the varying thickness of its hardened outer shell. Atypical bone morphologies, such as the ones present in hips suffering from Femoral Acetabular Impingements (FAIs) can also provide additional challenges to segmentation. We overcome these difficulties by (a) dividing the femur into the femur head and body regions (b) analysis of the femur-head and neighbouring acetabulum’s composition (c) segmentations with two levels of detail – rough and fine contours. Segmentations of the CT volume are performed iteratively, on a slice-by-slice basis and contours are extracted using the morphological snake algorithm. Our methodology was designed to require little initialization from the user and to deftly handle the large variation in femur shapes, most notably from deformations attributed to cam-type FAIs. Our efforts are to provide physicians with a new tool that creates patient-specific and high-quality 3D femur models while requiring much less time and effort. We tested our methodology on a database of 20 CT volumes acquired at the Ottawa General Hospital during a study into FAIs. We selected 6 CT scans from the database, for a total of 12 femurs, considering wide inter-patient variations. Of the 6 patients, 4 had unilateral cam-type FAIs, 1 had a bilateral cam-type FAI and the last was from a control group. The femurs segmented with our method achieved an average volume overlap error of 2.71 ± 0.44% and an average symmetric surface distance of 0.28 ± 0.04 mm compared against the same, manually segmented femurs. These results are better than all comparable literature and accurate enough to be used to in the creation of patient-specific 3D models.
5

Trajectory Estimation In Directional Drilling Using Bottom Hole Assembly(bha) Analysis

Dogay, Serkan 01 December 2007 (has links) (PDF)
The aim of this study is to combine the basic concepts of mechanics on drill string which are related to directional drilling, thus finding a less complicated and more economical way for drilling directional wells. Slick BHA, which has no stabilizers attached and single stabilizer BHA are analyzed through previously derived formulas gathered from the literature that are rearranged for this study. An actual directional well is redrilled theoretically with a slick BHA and a computer program is assembled for calculating the side force and direction of the well for single stabilizer BHA. Influence of controllable variables on drilling tendency is investigated and reported. The study will be useful for well trajectory and drill string design in accordance with the drilling phase. Also, by using available data from offset wells, drilling engineer can back-calculate the formation anisotropy index (FAI) that is often used for optimizing well trajectories and predicting drilling tendency on new wells in similar drilling conditions. After analysing the directional well data used in this study, it has been concluded that the well could be drilled without a steerable tool if the kick of point (KOP) is not a shallower depth. If the KOP is kept similar, the same curvature could not be achieved without a steerable tool.
6

3D Segmentation of Cam-Type Pathological Femurs with Morphological Snakes

Telles O'Neill, Gabriel 30 June 2011 (has links)
We introduce a new way to accurately segment the 3D femur from pelvic CT scans. The femur is a difficult target for segmentation due to its proximity to the acetabulum, irregular shape and the varying thickness of its hardened outer shell. Atypical bone morphologies, such as the ones present in hips suffering from Femoral Acetabular Impingements (FAIs) can also provide additional challenges to segmentation. We overcome these difficulties by (a) dividing the femur into the femur head and body regions (b) analysis of the femur-head and neighbouring acetabulum’s composition (c) segmentations with two levels of detail – rough and fine contours. Segmentations of the CT volume are performed iteratively, on a slice-by-slice basis and contours are extracted using the morphological snake algorithm. Our methodology was designed to require little initialization from the user and to deftly handle the large variation in femur shapes, most notably from deformations attributed to cam-type FAIs. Our efforts are to provide physicians with a new tool that creates patient-specific and high-quality 3D femur models while requiring much less time and effort. We tested our methodology on a database of 20 CT volumes acquired at the Ottawa General Hospital during a study into FAIs. We selected 6 CT scans from the database, for a total of 12 femurs, considering wide inter-patient variations. Of the 6 patients, 4 had unilateral cam-type FAIs, 1 had a bilateral cam-type FAI and the last was from a control group. The femurs segmented with our method achieved an average volume overlap error of 2.71 ± 0.44% and an average symmetric surface distance of 0.28 ± 0.04 mm compared against the same, manually segmented femurs. These results are better than all comparable literature and accurate enough to be used to in the creation of patient-specific 3D models.
7

The Effect of Femoroacetabular Deformity on Lower-Limb Joint Biomechanics During Daily Functional Tasks

Dwyer, Kevin 16 April 2014 (has links)
Femoroacetabular impingement (FAI) is a hip joint deformity that causes joint pain, decreases joint range of motion and results in abnormal kinematic and kinetic characteristics. It is not known whether these biomechanical variations are caused by the actual mechanical impingement aspect of hip deformity or neuromuscular adaptations and soft tissue damage associated with pain. The purpose of this study was to investigate the effects of femoroacetabular cam deformity (FAD) during daily functional tasks. This was accomplished by measuring and comparing the hip joint biomechanics of symptomatic FAI (sFAI), asymptomatic FAD, and control (CON) subjects. Fifty one subjects volunteered to the study (n = 51; CON = 17, FAD = 18, sFAI = 16) and they performed 6 simulated activities of daily living: stair ascent and descent, sit-to-stand and stand-to-sit, dynamic range of motion, maximum depth squats and level walking tasks while motion ground reaction force and muscle activity were recorded. However, only the squat and level walking tasks were analyzed for this thesis. For each task, three-dimensional kinematics and kinetics were recorded and analyzed. Qualitative questionnaires (HOOS and WOMAC) and physical exams were also part of the testing protocol, and maximum voluntary isometric contractions (MVIC) were collected as part of a separate EMG protocol. The EMG results were not analyzed but the MVIC results were and the moments of force were determined. The sFAI group had significantly reduced scores for all HOOS and WOMAC metrics compared to FAD and CON. The sFAI group had significantly reduced external rotation, internal rotation, and a trend indicating reduced hip flexion compared to FAD and CON groups. The FAD group had a trend indicating reduced internal rotation compared to CON. There were no differences in the moments of force between groups for the MVICs. No statistically significant differences were observed between groups for the squat trials, however, the sFAI group showed biomechanical variations. Both the CON and FAD groups were able to squat deeper, had greater pelvic range of motion and a larger maximum hip and knee flexion angle compared to sFAI. Similarly, the walking tasks did not elucidate any between group differences in biomechanical characteristics. Yet, there was a noticeable trend of decreased peak hip abduction angle in the sFAI group compared to CON. This result may be indicative of a gait adaptation based on the pain that sFAI subjects endure over a long period of time. Interestingly, the FAD group did not have obvious gait patterns similar to either the CON or sFAI, making it unclear if the asymptomatic cam deformity has any gait adaptation effects. Since no differences were observed between FAD and CON in squatting and walking, the actual bone deformity may not be the cause of restricted motion during daily activities as previously thought. Internal rotation physical examination appears to indicate potential restrictions in the FAD compared to CON, and may be the best parameter to assess differences between groups and predict the presence of cam deformity. It is suggested that the presence of pain, caused by soft tissue damage over time, may be confounding factors leading to the biomechanical and neuromuscular discrepancies observed in sFAI, and should be the next avenue of study.
8

Proposição de um método de detecção de FAI baseado nos componentes harmônicos de baixa frequência.

LIMA, Érica Mangueira. 03 May 2018 (has links)
Submitted by Emanuel Varela Cardoso (emanuel.varela@ufcg.edu.br) on 2018-05-03T20:55:24Z No. of bitstreams: 1 ÉRICA MANGUEIRA LIMA – DISSERTAÇÃO (PPGEE) 2016.pdf: 3788955 bytes, checksum: b005e5fd7bcddd43613e8d3de47b9e6c (MD5) / Made available in DSpace on 2018-05-03T20:55:25Z (GMT). No. of bitstreams: 1 ÉRICA MANGUEIRA LIMA – DISSERTAÇÃO (PPGEE) 2016.pdf: 3788955 bytes, checksum: b005e5fd7bcddd43613e8d3de47b9e6c (MD5) Previous issue date: 2016-07-28 / Capes / Um método baseado nos harmônicos de baixa ordem para detecção de faltas de alta impedância (FAI) é proposto nessa dissertação. A Short-Time Fourier Transform (STFT) é empregada para extração dos principais componentes harmônicos da corrente de fase proveniente de uma FAI, os quais são utilizados para identificar a ocorrência desse tipo de falta. Adicionalmente apresenta-se uma análise do tamanho e tipo da janela utilizada na transformada e sua adequação à aplicação. Para validação do método, duas bases de dados foram utilizadas: uma base contendo sinais simulados de FAI, chaveamento de bancos de capacitores e energização de linhas, e outra base contendo apenas registros oscilográficos reais de FAI. O método proposto é capaz de detectar a ocorrência de FAI em diferentes pontos do sistema, para diversos tipos de superfícies de solo e conseguiu também distinguir FAI dos outros distúrbios. Além disso, o método é tolerante aos ruídos que são próprios dos sinais reais, uma vez que se mostrou eficaz em todos os casos aos quais foram aplicados. / A method to detect high impedance faults (HIF) based on the low order harmonics is proposed on this dissertation. The Short-Time Fourier Transform (STFT) is used to extract the main harmonic components of the phase current, which are used to identify a HIF occurrence. Additionally, the work presents an analysis on the window size and type used in the STFT and its suitability for the application. The method is validated using two databases: one containing HIF simulated signals mixed up with capacitor banks switching and feeder energizing singals, and another containing only actual HIF oscillograms. The proposed method is able to detect HIF occurring in various points of the test-system, as well as HIF happening on different types of soil surfaces. It is also able to distinguish HIF from the other tested disturbances. Futhermore, the method tolerates typical noises present on real signals, since it proved to be effective in all the applied cases.
9

3D Segmentation of Cam-Type Pathological Femurs with Morphological Snakes

Telles O'Neill, Gabriel January 2011 (has links)
We introduce a new way to accurately segment the 3D femur from pelvic CT scans. The femur is a difficult target for segmentation due to its proximity to the acetabulum, irregular shape and the varying thickness of its hardened outer shell. Atypical bone morphologies, such as the ones present in hips suffering from Femoral Acetabular Impingements (FAIs) can also provide additional challenges to segmentation. We overcome these difficulties by (a) dividing the femur into the femur head and body regions (b) analysis of the femur-head and neighbouring acetabulum’s composition (c) segmentations with two levels of detail – rough and fine contours. Segmentations of the CT volume are performed iteratively, on a slice-by-slice basis and contours are extracted using the morphological snake algorithm. Our methodology was designed to require little initialization from the user and to deftly handle the large variation in femur shapes, most notably from deformations attributed to cam-type FAIs. Our efforts are to provide physicians with a new tool that creates patient-specific and high-quality 3D femur models while requiring much less time and effort. We tested our methodology on a database of 20 CT volumes acquired at the Ottawa General Hospital during a study into FAIs. We selected 6 CT scans from the database, for a total of 12 femurs, considering wide inter-patient variations. Of the 6 patients, 4 had unilateral cam-type FAIs, 1 had a bilateral cam-type FAI and the last was from a control group. The femurs segmented with our method achieved an average volume overlap error of 2.71 ± 0.44% and an average symmetric surface distance of 0.28 ± 0.04 mm compared against the same, manually segmented femurs. These results are better than all comparable literature and accurate enough to be used to in the creation of patient-specific 3D models.
10

The Effect of Femoroacetabular Deformity on Lower-Limb Joint Biomechanics During Daily Functional Tasks

Dwyer, Kevin January 2014 (has links)
Femoroacetabular impingement (FAI) is a hip joint deformity that causes joint pain, decreases joint range of motion and results in abnormal kinematic and kinetic characteristics. It is not known whether these biomechanical variations are caused by the actual mechanical impingement aspect of hip deformity or neuromuscular adaptations and soft tissue damage associated with pain. The purpose of this study was to investigate the effects of femoroacetabular cam deformity (FAD) during daily functional tasks. This was accomplished by measuring and comparing the hip joint biomechanics of symptomatic FAI (sFAI), asymptomatic FAD, and control (CON) subjects. Fifty one subjects volunteered to the study (n = 51; CON = 17, FAD = 18, sFAI = 16) and they performed 6 simulated activities of daily living: stair ascent and descent, sit-to-stand and stand-to-sit, dynamic range of motion, maximum depth squats and level walking tasks while motion ground reaction force and muscle activity were recorded. However, only the squat and level walking tasks were analyzed for this thesis. For each task, three-dimensional kinematics and kinetics were recorded and analyzed. Qualitative questionnaires (HOOS and WOMAC) and physical exams were also part of the testing protocol, and maximum voluntary isometric contractions (MVIC) were collected as part of a separate EMG protocol. The EMG results were not analyzed but the MVIC results were and the moments of force were determined. The sFAI group had significantly reduced scores for all HOOS and WOMAC metrics compared to FAD and CON. The sFAI group had significantly reduced external rotation, internal rotation, and a trend indicating reduced hip flexion compared to FAD and CON groups. The FAD group had a trend indicating reduced internal rotation compared to CON. There were no differences in the moments of force between groups for the MVICs. No statistically significant differences were observed between groups for the squat trials, however, the sFAI group showed biomechanical variations. Both the CON and FAD groups were able to squat deeper, had greater pelvic range of motion and a larger maximum hip and knee flexion angle compared to sFAI. Similarly, the walking tasks did not elucidate any between group differences in biomechanical characteristics. Yet, there was a noticeable trend of decreased peak hip abduction angle in the sFAI group compared to CON. This result may be indicative of a gait adaptation based on the pain that sFAI subjects endure over a long period of time. Interestingly, the FAD group did not have obvious gait patterns similar to either the CON or sFAI, making it unclear if the asymptomatic cam deformity has any gait adaptation effects. Since no differences were observed between FAD and CON in squatting and walking, the actual bone deformity may not be the cause of restricted motion during daily activities as previously thought. Internal rotation physical examination appears to indicate potential restrictions in the FAD compared to CON, and may be the best parameter to assess differences between groups and predict the presence of cam deformity. It is suggested that the presence of pain, caused by soft tissue damage over time, may be confounding factors leading to the biomechanical and neuromuscular discrepancies observed in sFAI, and should be the next avenue of study.

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