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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

Ergonomics integration and user diversity in product design

Hogberg, Dan January 2005 (has links)
Consideration of products' ergonomic qualities is one important component for successful product development. Product designers engaged in the core activity of product development need methods that support the consideration of ergonomics along with other product requirements. This thesis aims to address these needs. The first part of the thesis investigates how people working within product development organisations communicate with and about users of their products. The general need for methods to support communication of user aspects in product development is identified through formal interviews with product developers and a review of the management, ergonomics and design literature. The second part of the thesis studies the factors which affect the integration of ergonomics in product design. Supportive methods, including User Characters, for evoking user consideration among designers together with Overlapping methods for scheduling ergonomics evaluation in product design processes are introduced and argued. The third part of the thesis reviews and discusses computer aided ergonomics as a means for integration of ergonomics in product design. A web-based support system for effective employment of human simulation tools is developed using a participative approach and evaluated based on the system's usability. The objective of the fourth part of the thesis is to study how human simulation tools can aid designers' consideration of human diversity to accommodate users of diverse anthropometric characteristics in multivariate design problems such as automobile cockpits. The work involves the evaluation of different approaches for the generation of specific manikin families which can be used as test groups for fitting trials in the virtual design process. The research demonstrates enhancements in design methodology knowledge to support integration of ergonomics in product design processes with a focus on anthropometric diversity in vehicle design.
2

O uso de ferramentas de simulação humana para a avaliação de cargas físicas de trabalho: uma análise comparativa entre a aplicação em ambiente real na indústria aeronáutica e ambiente digital

Diniz, Ana Carolina Parise 20 May 2014 (has links)
Made available in DSpace on 2016-06-02T19:52:06Z (GMT). No. of bitstreams: 1 6106.pdf: 3970228 bytes, checksum: 4d17358d9e73dde70662d97121c7ee79 (MD5) Previous issue date: 2014-05-20 / This research introduces the use of digital human modeling packages Tecnomatic members (Simens) - Jack software - and Dassout System - Delmia software. This choice is justified by the representation of these packages in terms of industrial applications as well as by the availability of such PSPLab / DEP / UFSCar. The overall study aims: to assess the variability in responses between the results of both software and application of RULA, NIOSH and Snook and Ciriello tools in real environment. And as a specific goal: to characterize the application of these tools in both softwares and compare the performance of different softwares. While search procedures were selected common three softwares analysis tools (RULA, NIOSH and Snook and Ciriello) and applied the same work situations. As base of applications and modeling in software performed the procedures prescribed for application of the tools were made by the researcher. Thus, the same situation was analyzed in three contexts: application of the tool by the researcher in a real environment (P), in Delmia (D) and in Jack (J). The activities were selected according to what each tool aims to analyze. It was observed that the results of the RULA and Snook and Ciriello real environment and digital applications have been coming, since the results of the NIOSH applications in both environments were discrepant . It is concluded that the RULA and Snook and Ciriello tools can be applied in human simulations in softwares Delmia and Jack to assist ergonomic analysis of actual and future activities. Further studies are needed to validate the application of the NIOSH software. / Esta pesquisa apresenta a utilização das modelagens humanas digitais integrantes dos pacotes Tecnomatic/Simens (software Jack) e Dassout System (software Delmia). Tal escolha é justificada pela representatividade destes pacotes em termos de aplicações industriais bem como pela disponibilidade dos mesmos no PSPLab/DEP/UFSCar. O estudo teve como objetivo geral: avaliar a variabilidade nas respostas entre os resultados dos dois softwares e da aplicação em ambiente real das ferramentas RULA, NIOSH e Snook e Ciriello. E como objetivo específico: caracterizar a aplicação destas ferramentas e comparar o desempenho dos diferentes softwares. Enquanto procedimentos de pesquisa foram selecionadas três ferramentas de análise comuns aos softwares (RULA, NIOSH e Snook e Ciriello) e aplicadas nas mesmas situações de trabalho. Como balizador das aplicações e modelagens realizadas nos softwares, os procedimentos prescritos para aplicação das ferramentas foram realizados pelo pesquisador. Assim, uma mesma situação foi analisada em três contextos: aplicação das ferramentas pelo pesquisador em ambiente real (P), no Delmia (D) e no Jack (J). As atividades foram selecionadas de acordo com o que cada ferramenta visa analisar. Foi possível observar que os resultados das aplicações do RULA e do Snook e Ciriello em ambiente real e digital foram próximos, já os resultados das aplicações da NIOSH em ambos ambientes foram discrepantes. Conclui-se então que as ferramentas RULA e Snook e Ciriello podem ser aplicadas em simulações humanas nos softwares Delmia e Jack para auxiliar na análise ergonômica. E mais estudos são necessários para validar a aplicação da NIOSH nos softwares.
3

A computational model of human iron metabolism

Mitchell, Simon January 2013 (has links)
Iron is essential for virtually all organisms, yet it can be highly toxic if not properly regulated. Only the Lyme disease pathogen Borrelia burgdorferi has evolved to not require iron (Aguirre et al., 2013).Recent findings have characterised elements of the iron metabolism network, but understanding of systemic iron regulation remains poor. To improve understanding and provide a tool for in silico experimentation, a computational model of human iron metabolism has been constructed. COPASI was utilised to construct a model that included detailed modelling of iron metabolism in liver and intestinal cells. Inter-cellular interactions and dietary iron absorption were included to create a systemic computational model. Parameterisation was performed using a wide variety of literature data. Validation of the model was performed using published experimental and clinical findings, and the model was found to recreate quantitatively and accurately many results. Analysis of sensitivities in the model showed that, despite enterocytes being the only route of iron uptake, almost all control over the system is provided by reactions in the liver. Metabolic control analysis identified key regulatory factors and potential therapeutic targets. A virtual haemochromatosis patient was created and compared to a simulation of a healthy human. The redistribution of control in haemochromatosis was analysed in order to improve our understanding of the condition and identify promising therapeutic targets. Cellular prion protein (PrP) is an enigmatic protein, implicated in disease when misfolded, but its physiological role remains a mystery. PrP was recently found to have ferric-reductase capacity. Potential sites of ferric reduction were simulated and the findings compared to PrP knockout mice experiments. I propose that the physiological role of PrP is in the chemical reduction of endocytosed ferric iron to its ferrous form following transferrin receptor-mediated uptake.
4

Model predictive control for adaptive digital human modeling

Sheth, Katha Janak 01 December 2010 (has links)
We consider a new approach to digital human simulation, using Model Predictive Control (MPC). This approach permits a virtual human to react online to unanticipated disturbances that occur in the course of performing a task. In particular, we predict the motion of a virtual human in response to two different types of real world disturbances: impulsive and sustained. This stands in contrast to prior approaches where all such disturbances need to be known a priori and the optimal reactions must be computed off line. We validate this approach using a planar 3 degrees of freedom serial chain mechanism to imitate the human upper limb. The response of the virtual human upper limb to various inputs and external disturbances is determined by solving the Equations of Motion (EOM). The control input is determined by the MPC Controller using only the current and the desired states of the system. MPC replaces the closed loop optimization problem with an open loop optimization allowing the ease of implementation of control law. Results presented in this thesis show that the proposed controller can produce physically realistic adaptive simulations of a planar upper limb of digital human in presence of impulsive and sustained disturbances.
5

Design of a large-scale constrained optimization algorithm and its application to digital human simulation

Nicholson, John Corbett 01 May 2017 (has links)
A new optimization algorithm, which can efficiently solve large-scale constrained non-linear optimization problems and leverage parallel computing, is designed and studied. The new algorithm, referred to herein as LASO or LArge Scale Optimizer, combines the best features of various algorithms to create a computationally efficient algorithm with strong convergence properties. Numerous algorithms were implemented and tested in its creation. Bound-constrained, step-size, and constrained algorithms have been designed that push the state-of-the-art. Along the way, five novel discoveries have been made: (1) a more efficient and robust method for obtaining second order Lagrange multiplier updates in Augmented Lagrangian algorithms, (2) a method for directly identifying the active constraint set at each iteration, (3) a simplified formulation of the penalty parameter sub-problem, (4) an efficient backtracking line-search procedure, (5) a novel hybrid line-search trust-region step-size calculation method. The broader impact of these contributions is that, for the first time, an Augmented Lagrangian algorithm is made to be competitive with state-of-the-art Sequential Quadratic Programming and Interior Point algorithms. The present work concludes by showing the applicability of the LASO algorithm to simulate one step of digital human walking and to accelerate the optimization process using parallel computing.
6

Simulating Human Movement Patterns in an Area : A Part of the Crowdmapper Project

Svanberg, Rasmus, Svensson, Hampus January 2021 (has links)
In 2019, the Covid-19 pandemic struck the world, creating a need for social distancing to stop the spreading of the virus. This report will discuss and cover how a simulation was implemented in the game engine Unity that simulates human movement-patterns, which in turn will help with spreading people out in public areas. To be able to do this accurately, research was made about which behaviours can be of importance to get as realistic a representation of human movements as possible. The performed research showed that some contributing factors to get a realistic result includes how many destinations (e.g. in a Supermarket, a destination would be a shelf with wares) a human usually visits during a shopping trip to a supermarket. This is something that was quickly realized and could be used and implemented in the simulation, as it directly affects how long each human stays in the store, which in the long run makes crowds, and places where they form, more realistic. When the simulation was finished, a Google Forms was created, which were spread in numerous different groups on Facebook and Reddit, in which a total of 60 participants were registered. This quantitative research gave a good understanding of how the project had turned out and what could be improved. The results were very promising, and more or less what was hoped for. There is still room for further improvements, which are all mentioned in the chapter “Further Research” of this report. One example that is mentioned here is whether or not collisions between our simulated humans matter enough to make a difference to the end result. It is argued that it does not, but this is something one should perform further studies on.
7

Modelo de estima??o de multid?es pra cen?rios de emerg?ncia

Testa, Estev?o Smania 15 March 2018 (has links)
Submitted by PPG Ci?ncia da Computa??o (ppgcc@pucrs.br) on 2018-09-13T13:02:14Z No. of bitstreams: 1 ESTEVAO SMANIA TESTA_DIS.pdf: 3237172 bytes, checksum: d5aadd66e71bcae6b9ef00c5c31e0e5a (MD5) / Approved for entry into archive by Sheila Dias (sheila.dias@pucrs.br) on 2018-09-14T19:04:09Z (GMT) No. of bitstreams: 1 ESTEVAO SMANIA TESTA_DIS.pdf: 3237172 bytes, checksum: d5aadd66e71bcae6b9ef00c5c31e0e5a (MD5) / Made available in DSpace on 2018-09-14T19:26:34Z (GMT). No. of bitstreams: 1 ESTEVAO SMANIA TESTA_DIS.pdf: 3237172 bytes, checksum: d5aadd66e71bcae6b9ef00c5c31e0e5a (MD5) Previous issue date: 2018-03-15 / Planos de evacua??o t?m sido historicamente usados como uma medida de seguran?a para a constru??o de edif?cios. Os simuladores existentes requerem ambientes 3D totalmente modelados e tempo suficiente para preparar e simular cen?rios. Uma vez que a quantidade de pessoas pode mudar ao longo do tempo, v?rias simula??es s?o frequentemente necess?rias para gerar um plano de evacua??o otimizado. Neste documento ? apresentado uma nova abordagem para estimar os dados resultantes de um dado cen?rio de evacua??o sem simula-lo de fato. Para tal o ambiente ? dividido o ambiente em salas modulares com configura??es diferentes, em um estilo divis?o e conquista. Em seguida, uma rede neural artificial ? treinada para estimar os dados desejados de uma sala sozinha. Ap?s coletar os dados estimados de cada sala, uma heur?stica capaz de agregar informa??es por sala ? desenvolvida para que o ambiente completo possa ser devidamente estimado. Esse m?todo apresenta erros dentro da margem de 30% quando comparado o tempo de evacua??o em um ambiente real e complexo. Al?m disso, n?o ? necess?rio modelar o ambiente 3D, aprender como configurar um simulador de multid?es e o tempo computacional para estimar ? instant?neo quando comparado ao melhor caso de um simulador de multid?es. / Evacuation plans have been historically used as a safety measure for the construction of buildings. The existing simulators require fully-modeled 3D environments and enough time to prepare and simulate scenarios. Since the amount of people in a given simulated scenario can change over time, several simulations are often required in order to generate an optimal evacuation plan. With that in mind, we present in this paper a novel approach to estimate the resulting data of a given evacuation scenario without actually simulating it. For such, we divide the environment into modular rooms with different configurations, in a divide-and-conquer fashion. Next, we train an artificial neural network to estimate all required data regarding the evacuation of a single room. After collecting the estimated data from each room, we developed a heuristic capable of aggregating per room information so the full environment can be properly evaluated. Our method presents errors within the 30% margin when compared to evacuation time in a real and complex environment. In addition, it is not necessary to model the 3D environment, learn how to use and configure a crowd simulator, and the computational time to estimate is instantaneous when compared to a best case real-time crowd simulator.
8

Análise da aplicação de ferramenta computacional de modelagem e simulação humana no projeto de situações produtivas

Moura, Daniel Braatz Antunes de Almeida 09 February 2009 (has links)
Made available in DSpace on 2016-06-02T19:51:40Z (GMT). No. of bitstreams: 1 2245.pdf: 5872409 bytes, checksum: b12b83b426b4420e3e1477afb63c08df (MD5) Previous issue date: 2009-02-09 / This research aims at presenting the human modeling and simulation contextualized by Ergonomic Work Analysis (EWA) and Probable Future Activities to assist in the design of new workstations. Two case studies in which human simulation was applied using the software Jack were analyzed. The first case study concerns the design of a new attendance counter in a Governmental Postal Company. The second concerns the design of a workstation in the production line of surgical needles in an industry of hygiene and medical products. The results indicate the contributions and challenges of using such technology in projects aiming envisaging issues of health and productivity. The use of simulation together with the Ergonomic Work Analysis (EWA) enabled predicting probable future activities and the participation and integration of actors involved in these social process. / Esta pesquisa apresenta como a ferramenta computacional de Modelagem e Simulação Humana contextualizada pela Análise Ergonômica do Trabalho (AET) e pela análise da Atividade Futura Provável pode auxiliar nos processos de projeto de postos de trabalho. São analisados dois estudos de caso nos quais a Simulação Humana foi empregada com auxílio do software Jack (UGS Siemens). O primeiro estudo aborda a concepção de um balcão de atendimento em uma empresa pública de serviços postais. O segundo apresenta o desenvolvimento de uma estação de trabalho de abastecimento de agulhas cirúrgicas em uma empresa de manufatura de produtos relacionados as áreas de saúde e higiene. A partir dos resultados dos estudos de caso são explicitadas as contribuições e desafios da utilização dessa tecnologia em projetos de concepção, visando equacionar as questões do bem-estar humano e da produtividade. O uso da simulação, integrada ao processo de intervenção da AET, permitiu melhorar a antecipação das futuras atividades prováveis das novas situações de trabalho e auxiliou a integração e comunicação dos atores envolvidos nesses processos sociais.
9

A Geometric Approach for Discrete and Statistical Reach Analysis for a DHM with Mutable Supports

Reddi, Sarath January 2013 (has links) (PDF)
Conventional ergonomics analysis involves building physical mockups and conducting simulated operations, such that the constraints experienced by the human subjects can be directly observed. The limitations of this approach are that, they are resource intensive, less flexible for testing design variability and difficult to involve large number of subjects to account for population variability and thus, it is a reactive approach. With the advent of computer aided techniques, efforts are on to support ergonomics analysis processes for proactive design approaches. To achieve this, real scenarios are being simulated in virtual environments which include induction of representative human subjects into such envi-ronments and are termed as Digital Human Models (DHMs). The main challenge in the simulation of humans is to obtain the naturalness that is perceived in human interaction with the environment. This naturalness can be achieved by synergetically modeling the physical performance and cognitive aspects of humans in such a way that one aspect caters the requirements posed from the other. But in current DHMs, the various elements in the physical performance aspect are not in line with the requirements of higher level behav¬ioral/cogntive aspects. Towards meeting this objective, the influence of physical performance aspects of humans on achieving naturalness when DHM interacts with the virtual environment has been studied. In this work, the task of ’reach’ has been chosen for studying the influence of kinematic structure, posture modeling and stability aspects on achieving naturalness for both discrete and statistical humans. Also, a framework has been developed to give instructions based on relations between the segments of the body and objects in the environment. Kinematic structure is modeled to simulate the humans with varied dimensions taking care of the change of link fixations necessary for various tasks. The conventional techniques used to define kinematic structures have limitations in resolving the issues that arise due to change in link fixations. In this work a new scheme is developed to effectively handle precedence relationship sand change of configuration of the existing posture whenever link fixations change. The advantage with this new approach is that complex maneuvers which involve different link fixations and multiple fixations at a time can be managed automati¬cally without the user’s intervention. Posture prediction involves estimation of the whole body posture which a human operator is likely to assume while performing a task. It involves finding a configuration satisfy¬ing the constraints like placing the body-segments in preferred locations of the task space and satisfying the relations specified between body segments. There are two main chal¬lenges in this regard; one is achieving naturalness in the predicted postures and the other is minimizing the mathematical complexity involved in finding the real time solutions. A human-specific posture prediction framework is developed which can handle a variety of constraints and realize the natural behavior. The approach is completely geometry based and unlike numerical methods, the solutions involve no matrix inversions. Digital human models (DHMs), both as avatars and agents, need to be controlled to make them manipulate the objects in the virtual world. A relations based description scheme is developed to instruct the DHM to perform the tasks. The descriptions as a set of relations and postures involve simple triplets and quadruplets. As the descriptions constitute only the relations between actors, incorporating different behavior models while executing the relations is feasible through this framework. Static balancing is one of the crucial factors influencing the posture of humans. The stim¬ulus for the static balancing is the body’s self weight and is governed by the location of its point of application, namely the center of mass (COM). The main focus is on determin¬ing suitable locations for COM to infer about the mobility of the segments which supports the human structure in slow motion scenarios. Various geometric conditions necessary for support retaining, altering are deduced and developed strategies for posture transitions for effective task performance while maintaining stability. These conditions are useful in de¬termining the posture transition required to shift the COM from one region to the other and thus the behaviors realized while accomplishing the tasks are realistic. These behaviors are simulated through statically stable walking and sit to stand posture transition. One of the advantages of employing DHMs in virtual simulations is the feasibility of creat¬ing human models with varied dimensions. A comparative study is conducted on different methods based on probabilistic and statistic theory as an alternative to the percentile based approach with a view to answer the questions like ’what percentage of people can success-fully accomplish a certain task’ and ’how well can people perform when they reach a point in the operational space’. The case study is done assuming upper and lower arms of hu¬mans as a two link planar manipulator and their link lengths as random variables. Making use of statistical DHMs, the concept of task dependent boundary manikins is introduced to geometrically characterize the extreme individuals in the given population who would ac-complish the task. Simulations with these manikins would help designers to visualize how differently the extreme individuals would perform the task. All these different aspects of DHM discussed are incorporated in our native DHM developed named ’MAYAMANAV’. Finally this thesis will end with conclusions and future work discussing how these different aspects of DHM discussed can be combined with behavioral models to simulate the human error.

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