Performance Evaluation of Cyclist’s Position Using a Depth Camera-Based Motion Capture System

L’optimisation de la posture d’un cycliste peut améliorer les performances et réduire la traînée aérodynamique. Les cyclistes visent à améliorer leurs performances en réduisant le temps et l’e˙ort que leur demande la course cycliste. Toute modification de la position du cycliste pour améliorer la performance globale exige une compréhension fondamentale de ses carac-téristiques, notamment aérodynamiques, physiologiques et biomécaniques, ce qui constitue la principale préoccupation de la recherche sur le cyclisme. Les méthodes actuelles font appel à des techniques coûteuses et compliquées, d’où la nécessité d’une approche fonctionnelle et abordable qui tienne compte de tous les paramètres concernés. Cette recherche vise à développer une application fonctionnelle permettant d’évaluer l’e˙et de la position et du guidon sur l’aérodynamique et les performances d’un cycliste. La première partie de cette thèse porte sur le développement et la validation d’un ensemble d’outils paramétrés permettant de modéliser un mannequin numérique 3D représentant un cycliste professionnel à l’aide d’un système de capture de mouvement sans marqueur. De plus, la méthodologie développée a été appliquée pour analyser numériquement la traînée aérodynamique de di˙érentes positions statiques de cyclisme en utilisant la dynamique des fluides numérique (CFD). Les résultats montrent que le système sans marqueur convient parfaitement à la modélisation et à l’étude de la dynamique des fluides numérique. Le cadre de modélisation paramétré combiné à la CFD s’avère un outil précieux pour évaluer avec précision la traînée associée aux di˙érentes positions du cycliste. La deuxième partie de cette thèse examine les e˙ets de la modification de la position du guidon aérodynamique sur le schéma d’activation musculaire des extrémités inférieures et sur les variables cinématiques, attendu que tout ajustement de la position de cyclisme induit un changement dans la relation entre la posture du corps et la géométrie de la bicyclette, a˙ectant la performance physique. L’électromyographie de surface et la cinématique articu-laire du membre inférieur droit pendant le pédalage sur ergomètre ont été mesurées pour les cyclistes et triathlètes de compétition. Les expériences portent sur di˙érentes positions du cycliste au cours d’épreuves contre-la-montre, dans le but de déterminer l’e˙et de la modifi-cation de la position de l’aéro-guidon lors de six exercices à charge constante sous-maximale. L’abaissement de la hauteur du guidon aérodynamique a révélé une amélioration des perfor-mances cyclistes grâce à la contribution plus importante de l’extenseur de la hanche et de l’angle d’extension de la hanche. La méthodologie développée permet d’étudier les réponses physiologiques du cycliste et d’e˙ectuer une analyse aérodynamique détaillée lors de la modification de la position du guidon en contexte d’épreuves contre-la-montre, compte tenu de la contribution du cycliste à l’essentiel de la force de traînée du système cycliste-vélo. Les résultats suggèrent que par rap-port à la position préférée lors du contre-la-montre, la zone frontale, le coeÿcient de traînée et la zone de traînée ont été réduits lors de l’abaissement de la position du guidon alors que toutes les variables physiologiques sont restées inchangées. Cette thèse présente une approche unique permettant d’étudier la contribution des modifica-tions d’ajustement du guidon sur les performances aérodynamiques et biomécaniques du vélo. Ce système de capture du mouvement sans marqueur, peu coûteux, conçu pour mesurer et analyser la cinématique du vélo, peut fournir des données fiables et applicables à une analyse aérodynamique et biomécanique plus poussée.----------ABSTRACT Optimizing the posture of a cyclist can ameliorate performance and reduce the aerodynamic drag. Cyclists aim to enhance performance decreasing the time and e˙ort during the cycling race. Any modification of the cycling position to improve the overall performance demands a fundamental understanding of its characteristics, including aerodynamics, physiological and biomechanical features, which is the primary concern of cycling research. Current methods require costly and complicated techniques, and therefore, the necessity of a functional and a˙ordable approach that considers all the involved parameters is apparent. This research aims to develop a feasible application for evaluating the e˙ect of cycling position and aero handlebar on the aerodynamics and performance of a cyclist. The first part of this thesis focuses on developing and validating a set of parameterized tools to model a 3D digital manikin of professional cyclists using a markerless motion capture system. Furthermore, the developed methodology has applied to numerically analyze the aerodynamic drag of di˙erent static cycling positions using computational fluid dynamics (CFD). Results show that the markerless system is fully capable of modeling and providing the requirement of CFD investigation. The parameterized modeling framework combined with CFD is found to be a valuable tool to accurately evaluate the drag of di˙erent cyclist positions. The second part of this thesis explores changing the aero handlebar position on the lower extremities’ muscle activation pattern and kinematic variables since any adjustment in the cycling position induces a change in the relation between body posture and bicycle geometry, a˙ecting physical performance. The surface electromyography and joint-level kinematics of the right lower limb during cycling on an ergometer were measured for competitive road cyclists and triathletes. The experiments cover di˙erent time trial positions of the cyclist intending to determine the e˙ect of alteration of aero handlebar position in six submaxi-mal constant load exercises. Lowering the aero handlebar height showed improved cycling performance due to the more significant hip extensor contribution and extended hip angle. The developed methodology is applied to investigate the cyclist’s physiological responses and detailed aerodynamic analysis when altering the time trial handlebar position, considering the rider contributes most of the rider-bicycle system’s drag force. Findings suggest that compared to the preferred time trial position, the frontal area, drag coeÿcient and drag area were reduced when lowering the handlebar position while all the physiological variables remained unchanged. This thesis presents a unique approach to investigate the contribution of handlebar alterations on cycling aerodynamics and biomechanical performance. This low-cost markerless motion capture system for measuring and analyzing cycling kinematics can provide reliable and applicable data for further aerodynamics and biomechanical analysis

A new scaling equation for imbibition process in naturally fractured gas reservoirs

 Spontaneous imbibition is an important mechanism in naturally fractured reservoirs. Efforts were made to study matrix-fracture interaction where matrix blocks are surrounded by water-filled fractures by developing the scaling groups. Despite previous studies about the scaling groups introduced to characterize the imbibition process in oil reservoirs, gas reservoirs have been less considered. In this paper, the effects of various factors on the spontaneous imbibition in the gas reservoirs were investigated and by inspectional analysis, a modified scaling equation was introduced. The proposed scaling equation includes a variety of fluid and rock parameters. Furthermore, the efficiency of the presented scaling equation was tested in several cases with considerable different fluid and rock properties. The imbibition process in these cases were simulated by means of a realistic procedure. A comparison of the performance results of the new scaling equation for the defined cases showed much better accuracy for the imbibition scaling in the gas reservoirs by means of the presented scaling group in this work.Cited as: Ghasemi, F., Ghaedi, M., Escrochi, M. A new scaling equation for imbibition process in naturally fractured gas reservoirs. Advances in Geo-Energy Research, 2020, 4(1): 99-106, doi: 10.26804/ager.2020.01.0

Manifestation of Social Trust among Migrants: The Case of Iranian Residents in Toronto, Canada

This paper is excerpted from a research project titled “A Sociological Analysis of Socio-economic Situation of Iranian Migrants in Canada (Case Study: Toronto). This survey research has been carried out in 2005. Its main goal is to answer the following questions: What is the trust level among Iranian migrants residing in Toronto? What is the difference between the in-group social trust level (trust among Iranians) and the out-group trust level (confidence toward Canadians living in Toronto)? In an attempt to answer these questions a sample of 182 Iranians were interviewed on the basis of a standardized questionnaire. The findings reveal that the in-group social trust level – as measured against the defined scale – is slightly below the average, whereby the difference from the middle point of the scale is statistically significant. Moreover, it demonstrates that the mean figure for out-group social trust is significantly higher than the average defined on the scale. The results also suggest that the most important cause for lower in-group trust should be sought for in the pre- migration period. Researches carried out on social confidence indicate that weakness of social trust in home country is often transferred to other countries – after migration – and is intensified due to problems of the migrant community and increase of social risk

Evaluation of removal efficiency of phenol from synthetic aqueous solutions by Citrullus colocynthis seed ash

Background: Phenol is a prevalent pollutant found in many industrial wastewaters, and it is paid singular attention because of its special features like high toxicity, carcinogenic properties, and vital gathering ability that affects the health of humans and the environment. One of the most important technologies for the removal of phenol is the use of adsorbents. The current study investigated the removal of phenol from synthetic aqueous solutions using Citrullus colocynthis seed ash. Methods: This study is experimental and was conducted on a pilot scale. The efficiency of phenol removal by C. colocynthis seed ash was evaluated in a batch system, and different parameters such as initial concentration of phenol (10, 20, 50, and 80 mg/L), contact time (2, 5, 10, and 30 minutes), pH (2-12), adsorbent dose (0.5, 1, 3, 5, and 10 g/L), and temperature were studied. Excel software was used for data analysis. The adsorption process was modeled with Freundlich and Langmuir isotherms at controlled temperatures. Results: The results showed that the highest removal rate of phenol was obtained at a pH of 2 (83.4%), initial phenol concentration of 20 ppm (66.4%), adsorbent dose of 5 g/L (86.8%), and contact time of 10 minutes. The evaluation of correlation coefficients showed that the phenol adsorbed by C. colocynthis seed ash was in greater accordance with the Freundlich model than the Langmuir model. Conclusion: In general, the results of this study revealed that C. colocynthis seed ash has suitable potential for use in removing phenol from aqueous solutions on operation and practical scales due to its low cost and easy access. Keywords: Phenol, Adsorption, Citrullus colocynthi

Precision medicine and molecular imaging: new targeted approaches toward cancer therapeutic and diagnosis

Abstract: This paper presents a review of the importance and role of precision medicine and molecular imaging technologies in cancer diagnosis with therapeutics and diagnostics purposes. Precision medicine is progressively becoming a hot topic in all disciplines related to biomedical investigation and has the capacity to become the paradigm for clinical practice. The future of medicine lies in early diagnosis and individually appropriate treatments, a concept that has been named precision medicine, i.e. delivering the right treatment to the right patient at the right time. Molecular imaging is quickly being recognized as a tool with the potential to ameliorate every aspect of cancer treatment. On the other hand, emerging high-throughput technologies such as omics techniques and systems approaches have generated a paradigm shift for biological systems in advanced life science research. In this review, we describe the precision medicine, difference between precision medicine and personalized medicine, precision medicine initiative, systems biology/medicine approaches (such as genomics, radiogenomics, transcriptomics, proteomics, and metabolomics), P4 medicine, relationship between systems biology/medicine approaches and precision medicine, and molecular imaging modalities and their utility in cancer treatment and diagnosis. Accordingly, the precision medicine and molecular imaging will enable us to accelerate and improve cancer management in future medicine

Effect Assessment of Parkinson Disease on Default Mode Network of the Brain with ICA and SCA Methods in Resting State FMRI Data

Abstract Parkinson's disease (PD) is a progressive neurological disorder characterized by tremor, rigidity, and slowness of movements. Determining changes of spontaneous activity and connectivity of the brain is a critical step towards treatment of PD patients. Resting State functional Magnetic Resonance Imaging (RS-fMRI) is a non-invasive method that we use in this work to investigate changes of default mode network of the brain in PD. To this end, we apply two methods, Seed Correlation Analysis (SCA) and probabilistic independent Component Analysis (PICA). The results of advanced statistical group analysis on SCA values show that there is negative significant correlation between motor cortex and cerebellum in healthy, while this connection in PD is positive and not significant. This result implies the disturbance of equilibrium function of the brain in resting. Moreover, in both groups, there is significant positive correlation between areas located in basal ganglia. The results show that in healthy, there is not significant correlation between motor areas and basal ganglia, while in PD there are significant negative correlations between motor cortex and cerebellum with areas located in basal ganglia. The comparison of five ICs extracted by PICA showed lower DMN activation in basal ganglia. Finally, The result of our study show that the functional correlations between ROIs are more affected in PD than pattern maps of activity by PICA

RELATION BETWEEN ANTHROPOMETRIC DATA AND PERFORMANCE OF LOWER LIMB IN SQUAT JUMP

In this study, the total peak of joints’ torque, work, and the maximum jump height were measured in ten physically active male subjects performing the squat jump (SJ), and squat jump with arm swing (SJA). Accordingly, arm swing caused an increment in the heights of squat jump (p\u3c0.001).The results revealed relationships between body mass and height with the total peak of joints’ torque (0.5

The potential therapeutic use of renin-angiotensin system inhibitors in the treatment of inflammatory diseases

Inflammation is a normal part of the immune response to injury or infection but its dysregulation promotes the development of inflammatory diseases, which cause considerable human suffering. Non-steroidal anti-inflammatory agents (NSAIDs) are the most commonly prescribed agents for the treatment of inflammatory diseases but they are accompanied by a broad range of side effects, including gastrointestinal and cardiovascular events. The renin-angiotensin system (RAS) is traditionally known for its role in blood pressure regulation. However, there is increasing evidence that RAS signalling is also involved in the inflammatory response associated with several disease states. Angiotensin II increases blood pressure by binding to angiotensin type 1 (AT1) receptor, and direct renin inhibitors (DRIs), angiotensin-converting enzyme (ACE) inhibitors and AT1 receptor blockers (ARBs) are clinically used as anti-hypertensive agents. Recent data suggest that these drugs also have anti-inflammatory effects. Therefore, this review summarizes these recent findings for the efficacy of two of the most widely used antihypertensive drug classes, ACE inhibitors and ARBs, to reduce or treat inflammatory diseases such as atherosclerosis, arthritis, steatohepatitis, colitis, pancreatitis and nephritis

Aromatherapy Massage vs. Foot Reflexology on the Severity of Restless Legs Syndrome in Female Patients Undergoing Hemodialysis

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