Spelling suggestions: "subject:"body model"" "subject:"vody model""
1 |
On Quaternions and Activity Classification Across Sensor DomainsDennis, Jacob Henry 17 January 2015 (has links)
Activity classification based on sensor data is a challenging task. Many studies have focused on two main methods to enable activity classification; namely sensor level classification and body-model level classification. This study aims to enable activity classification across sensor domains by considering an e-textile garment and provide the groundwork for transferring the e-textile garment to a vision-based classifier. The framework is comprised of three main components that enable the successful transfer of the body-worn system to the vision-based classifier. The inter-class confusion of the activity space is quantified to allow an ideal prediction of known class accuracy for varying levels of error within the system. Methods for quantifying sensor and garment level error are undertaken to identify challenges specific to a body-worn system. These methods are then used to inform decisions related to the classification accuracy and threshold of the classifier. Using activities from a vision-based system known to the classifier, a user study was conducted to generate an observed set of activities from the body-worn system. The results indicate that the vision-based classifier used is user-independent and can successfully handle classification across sensor domains. / Master of Science
|
2 |
Evaluation of occupant kinematics in crash using the PIPER model : in frontal and oblique crash simulations / Evaluering av passagerarkinematik i krock med hjälp av PIPER modellen : i frontal och vinklade krock simuleringarDaouacher, Maria January 2019 (has links)
A child dies in road traffic crashes every fourth minute. Totally were 186 300 children under the age of 18 killed in vehicle accidents in 2012, even more were severely injured [1]. The World Health Organisation (WHO) could conclude that fatalities in traffic accidents are more likely to occur in low- to middle income countries compared to high income countries [1]. Finite element based human body models has enabled the increased understanding of kinematics and injury mechanisms of child occupants. These models sustain higher biofidelity than the previously used crash test dummies. The European project PIPER [6] had the aim to develop a model that, combined with a framework, would simplify positioning and also to offer a scalable HBM child model. The PIPER framework software and the scalable PIPER model offers child HBM:s within the ages 1.5-6-years old and is an useful tool for the analysis of child occupants. The present study evaluates the kinematics and dummy responses of the 4- and 6-year old PIPER model evaluated. The objective of this master thesis is to evaluate the PIPER model with respect to its sensitivity to seat belt geometries, child restraint system, load cases and child anthropometrics. The aim of the master thesis is to get an increased comprehension of the PIPER model and its capability to evaluate occupant kinematics relevant for safety developments, with a special focus on seat belt geometry and interaction in frontal impacts. The PIPER model showed good sensitivity to different seatbelt geometries regarding the abdominal part of the shoulder belt and to different CRS. The PIPER framework was perceived as hard to use and with the presence of errors. The kinematic response showed good accuracy compared to other previous studies with other crash test dummies however, reoccurring error termination could not be neglectable. The PIPER model is limited to its ease to positioning in desired sitting postures within the PIPER framework. It is regardless of its disadvantages believed to be a suitable tool to further understand occupant kinematics, as for different belt routings, child anthropometrics and dummy responses are further studies needed to validate the outputs that the model offers and to conclude its robustness in crashworthiness tests.
|
3 |
Analýza uložení zadního kola formulového vozidla / Formula Car Rear Wheel Carrier AnalysisOravec, Peter January 2019 (has links)
This diploma thesis is focused on Formula Student upright analysis using final element method. The main goal is to review an effect of different boundary conditions on stress and deformation. Nowadays, the topologic optimization is a commonly used tool for design process of the upright, to create the lightest and the most rigid design possible. Boundary conditions, which should approximate reality really well, are one of inputs to topological optimization.
|
4 |
COMPUTATIONAL MODELING OF A SCALABLE HUMAN BODY AND DEVELOPMENT OF A HELMET TESTING DIGITAL TWINSean Bucherl (12463827) 26 April 2022 (has links)
<p>Human body models (HBMs) have been present in the automotive industry for simulating automotive related injury since the turn of the century and have in recent years found a place in assessment of soldier and sports related injury prediction and assessment. This issue is the lack of models that lie outside of the 50th percentile. By a simple application of physics, it is evident that acceleration or force will affect people of varying weights differently. To this end, having the ability to scale a 50th percentile HBM to targets for weight and stature would allow for better characterization on how an impact or acceleration event will affect people of differing size, especially when ~90% of males can fall outside the 50th percentile for weight and stature and HBMs models from vendors exist in only a few variations outside the 50th percentile [1]. Using Corvid Technologies’ 50th percentile model CAVEMAN (capable of being repositioned) as a base, scaled model from the 5th to 95th percentiles of stature and weight were generated based on ANSURII metrics, using a combination of 1D and 3D scaling transformations. These models met their stature and weight metrics when standing and weight metrics when positioned. </p>
<p>After creation of a framework to scale the CAVEMAN HMB, creation of a digital twin to the HIRRT Lab helmet testing model commenced. With the HIRRT Lab’s history of experimental testing of football helmets, a natural turn of events was to bring helmet performance testing into the computational space. This digital twin was a natural evolution and addition to the HIRRT Lab’s helmet testing as it would enable manipulation of helmets that would be infeasible experimentally. After calibration of the barehead using experimental data, helmeted simulation began. Angle of impact, while it was found to effect peak translational acceleration, was found to profoundly effect peak rotational acceleration. With this in mind, various angles of impact were simulated to produce curves similar to experimental results. Helmeted simulations were qualitatively dissimilar to experimental data, prompting a modification of the padding material used by the models. Following various modifications of the padding material model, these inconsistencies between simulated helmets and experimentally tested helmets persisted. These inconsistencies highlight a need for better characterization of material, such as foam, and more thorough validation of simulated helmet models. The results of the helmeted simulations are difficult to quantify, as the evaluation criteria used for the BioCore model did not include rotational acceleration, indicating a need for further research and simulation is necessary. </p>
|
5 |
Modeling, Design, and Testing of Contact-Aided Compliant Mechanisms in Spinal ArthroplastyHalverson, Peter Andrew 08 July 2010 (has links) (PDF)
Injury, instrumentation, or surgery may change the functional biomechanics of the spine. Spinal fusion, the current surgical treatment of choice, stabilizes the spine by rigid fixation, reducing spinal mobility at the cost of increased stress at adjacent levels. Recently, alternatives to spinal fusion have been investigated. One such alternative is total disc replacements. The current generation of total disc replacements (TDRs) focuses on restoring the quantity of motion. Recent studies indicate that the moment-rotation response and axis of rotation, or quality of motion (QOM), may have important implications in the health of adjacent segments as well as the health of the surrounding tissue of the operative level. This dissertation examines the use of compliant mechanism design theory in the design and analysis of spinal arthroplasty devices. Particularly, compliant mechanism design techniques were used to develop a total disc replacement capable of replicating the normal moment-rotation response and location and path of the helical axis of motion. Closed-form solutions for the device's performance are proposed and a physical prototype was created and evaluated under a modified F1717 and a single-level cadaveric experiment. The results show that the prototype's QOMclosely matched the selected force-deflection response of the specified QOM profile. The use of pseudo-rigid-body modeling to evaluate the effects of various changes on motion at adjacent segments is also investigated. The ability to model biomechanical changes in the spine has traditionally been based on animal models, in vitro testing, and finite element analysis. These techniques, although effective, are costly. As a result, their use is often limited to late in the design process. The pseudo-rigid-body model (PRBM) developed accurately predicted the moment-rotation response of the entire specimen and the relative contribution of each level. Additionally, the PRBM was able to predict changes in relative motion patterns of the specimen due to instrumentation.
|
6 |
Quantitative investigation of the effect of diet on the risk of developing metabolic syndrome using a computational whole-body model of metabolismAlessi, Drew 13 February 2024 (has links)
Metabolic Syndrome (MetS) is a cluster of metabolic disorders that substantially increase the risk of developing other chronic diseases such as cardiovascular disease and type II diabetes. Diet is known to play a crucial role in the development of MetS and dietary intervention studies are a useful tool to investigate the effect of diet on MetS. However, the slow onset of MetS and difficulties associated with adhering to new diets, especially for long-term, makes it challenging to perform extensive dietary intervention studies on humans. To overcome this limitation, we sought to investigate the impact of diet on the risk of MetS by taking an in silico systems biology approach. We employed a whole-body model (WBM) of metabolism that accounts for 26 organs, including six sex organs, to computationally evaluate, at genome-scale, the effect of ten different diets on the serum levels of five key metabolites implicated in MetS namely glucose, triacylglycerides (TAG), LDL-C, HDL-C, and palmitoyl-CoA. We performed separate simulations for males and females using the sex specific WBMs. Our analyses elucidated molecular mechanisms that support the current hypothesis that an unhealthy diet can significantly elevate the risk of developing MetS while a healthy diet helps promote metabolic homeostasis. Furthermore, our investigation uncovered novel insights into the contribution of specific organs and tissues to the risk of MetS under these diets in males and females. For example, we found that glucose and TAG secretion by adipocytes into the blood are substantially lower and higher, respectively, under the unhealthy diet compared to other diets. Striking differences were also observed between the unhealthy diet and other diets for LDL-C, HDL-C, and palmitoyl-CoA in males. In females, we observed patterns that resembled those in males although other organs, such as the breast or uterus, also contributed to the serum levels of these key metabolites. Our study offers a promising strategy for investigating the effect of various dietary regimens on human metabolism and MetS at organ-level resolution. This paves the way for the in silico design of new dietary interventions to treat MetS. / 2026-02-12T00:00:00Z
|
7 |
Development of a Discretized Model for the Restricted Three-Body ProblemJedrey, Richard M. 28 July 2011 (has links)
No description available.
|
8 |
Built-in self-test in integrated circuits - ESD event mitigation and detectionEatinger, Ryan Joseph January 1900 (has links)
Master of Science / Department of Electrical Engineering / William Kuhn / When enough charges accumulate on two objects, the air dielectric between them breaks down to create a phenomenon known as electrostatic discharge (ESD). ESD is of great concern in the integrated circuit industry because of the damage it can cause to ICs. The problem will only become worse as process components become smaller.
The three main types of ESD experienced by an IC are the human body model (HBM), the charged device model (CDM), and the machine model (MM). HBM ESD has the highest voltage while CDM ESD has the highest bandwidth and current of the three ESD types.
Integrated circuits generally include ESD protection circuitry connected to their pads. Pads are the connection between the IC and the outside world, making them the required location for circuitry designed to route ESD events away from the IC's internal circuitry. The most basic protection pads use diodes connected from I/O to VDD and I/O to ground. A voltage clamp between VDD and ground is also necessary to protect against CDM and MM event types where the device may not yet have a low impedance supply path connected.
The purpose of this research is to investigate the performance of ESD circuits and to develop a method for detecting the occurrence of an ESD event in an integrated circuit by utilizing IC fuses. The combination of IC fuses and detection circuitry designed to sense a broken fuse allows the IC to perform a built-in self-test (BIST) for ESD to identify compromised ICs, preventing manufacturers from shipping damaged circuits.
Simulations are used to design an optimized protection circuit to complement the proposed ESD detection circuit. Optimization of an ESD pad circuit increases the turn-on speed of its voltage clamps and decreases the series resistance of its protection diodes. These improvements minimize the stress voltage placed on internal circuitry due to an ESD event. An ESD measurement setup is established and used to verify voltage clamp operation.
This research also proposes an ESD detection circuit based on IC fuses, which fail during an ESD event. A variety of IC fuses are tested using the ESD measurement setup as well as a TLP setup in order to determine the time and current needed for them to break. Suitable IC fuses have a resistance less than 5 Ω and consistently break during the first trial.
|
9 |
Détermination du rôle moteur complexe lombo-pelvi-fémoral sur la performance d'un mouvement explosif : approche expérimentale et simulation appliquées au squat jump / Determination of the motor function of the lumbo-pelvic-hip complex during explosif movement : experimental approach and simulation model applied to squat jumpBlache, Yoann 28 November 2012 (has links)
Le complexe lombo-pelvi-fémoral est une zone charnière du corps humain. Son rôle d’équilibration a étédémontré à de nombreuses reprises alors que sa fonction motrice, lors de mouvements explosifs requérant uneextension totale de la chaine articulaire, a été peu étudiée. Ainsi, l’objectif de ce travail a été d’évaluer le rôle moteurdu complexe lombo-pelvi-fémoral lors d’un mouvement de squat jump. A cet effet, une approche expérimentale(cinématique, dynamique et électromyographique) couplée à un modèle de simulation du système musculo-squelettiqueont été appliqués à l’analyse du squat jump dans le plan sagittal. Les résultats montrent, dans un premier temps, que lesétudes ne prenant pas en compte le complexe lombo-pelvi-fémoral conduisent à des erreurs de surestimation du travailmécanique attribué à l’articulation de la hanche lors de squat jumps avec ou sans balancé de bras. Dans un secondtemps, il apparaît que l’extension du rachis lombaire permise par l’erector spinae participe à l’atteinte d’une hauteurmaximale de saut. Ceci confirme l’hypothèse du rôle moteur du complexe lombo-pelvi-fémoral, soulignant égalementla contribution effectrice du muscle erector spinae, qui est accrue avec l’augmentation de sa force maximale et lorsd’une flexion initiale du tronc importante. En conclusion, il semble pertinent d’intégrer le complexe lombo-pelvifémoraldans l’analyse du squat jump en vue d’ouvrir de nouvelles perspectives d’entrainement visant à l’améliorationde la détente verticale. / The lumbo-pelvic-hip complex is an important structure of the human body. Its function of balancing the bodyhas been pointed out in many studies. While its motor function has rarely been investigated, especially duringexplosive movements involving a global extension of the whole body. Thus, the purpose of this work was to evaluatethe role of the lumbo-pelvic-hip complex during squat jumping. To this end, an experimental approach (kinematics,kinetics and electromyographic) as well as a simulation model of the musculoskeletal system have been used to analyzethe squat jump in the sagittal plan. The results show, firstly that studies which do not take into consideration the lumbopelvic-hip complex, lead to an overestimation of the mechanical work attributed to the hip joint during maximal squatjumps performed arms akimbo or with an arm swing. Secondly, the extension of the lumbar spine enabled by theerector spinae activation contributes to achieve a maximal vertical jump height. This result confirms the assumptionsabout the motor function of the lumbo-pelvic-hip complex and the erector spinae. Moreover, the contribution of thismuscle is increased when its maximal strength is enhanced and when the trunk is initially flexed. In conclusion, itseems relevant to take into consideration the lumbo-pelvic-hip complex when maximal squat jumping is studied. Thiswould also contribute to new training perspectives in order to improve maximal vertical jump height.
|
10 |
潜堤上の構造物に作用する波力とその算定法に関する研究水谷, 法美, MIZUTANI, Norimi, 許, 東秀, HUR, Dong-Soo 08 1900 (has links)
No description available.
|
Page generated in 0.1113 seconds