Thesis (MScPhysio)--Stellenbosch University, 2015 / ENGLISH ABSTRACT: Background: The use of computers at school, university, work and for social media is growing and whilst neck pain is common in the general population, computer users have an even higher prevalence. Incorrect workstation ergonomics have been identified as a risk factor for the development of neck pain in computer workers. Aims: To assess the effect of adjusting chair and monitor height of a female office worker’s computer workstation on work related neck and upper back pain intensity, comfort of her sitting posture and disability. Methods: An N=1 study was conducted using the A-B-C design consisting of a computer workstation adjustment involving chair and monitor height of a female office worker. The effect of the intervention was evaluated using the Visual Analogue Scale (VAS) to measure neck and upper back pain intensity and comfort of sitting position, and the Neck Disability Index to measure disability. The effect of the intervention was assessed over the three phases, consisting of four weeks each. During these phases, the participant could continue with her usual computer work. The results were compiled and tabulated. Results: A reduction in neck and upper back pain intensity as well as an increase in sitting comfort position were found. However these improvements were not statistically or clinically significant. The effect size for pain intensity was 0.76 and for sitting comfort 0.21. The participant reported no disability as measured by the Neck Disability Index, at the start and at the end at the end of the study. Conclusion: The vertical adjustment of this female office worker’s chair and monitor height according to her anthropometrics improved neck and upper back pain intensity and comfort of sitting position. This ergonomic workstation intervention could form part of a practical management option for computer users with neck and upper back pain. Further research is recommended to establish whether these findings are generalizable to the wider community of computer users. / AFRIKAANSE OPSOMMING: Probleemstelling: Die gebruik van rekenaars by skole, universiteite, werksplekke en vir sosiale doeleindes neem toe. Nek pyn kom dikwels in die algemene bevolking voor, maar dit is meer prevalent in rekenaargebruikers. ‘n Werkstasie wat nie ergonomies korrek opgestel is nie, is geidentifiseer as ‘n risikofaktor vir die ontwikkeling van nekpyn in rekenaar werkers. Doelwitte: Om te bepaal of aanpassings in die stoel- en beeldskerm hoogte van ‘n vroulike kantoor werker se rekenaar werkstasie, ‘n effek het op werksverwante nek en boonste rug pyn, sitgemak en funksionele vermoë. Methode: Die N=1 studie met ‘n A-B-C ontwerp is onderneem en het bestaan uit n rekenaar werkstasie aanpassing waarby die hoogte van die stoel en beeldskerm van ‘n vroulike relenaargebruiker aangepas is. Die effek van die intervensie is ge-evalueer deur middle van die visueel analoogskaal (VAS) om pyn en sitgemak te bepaal; en die Nek Ongeskiktheids Indeks (NOI) om gestremtheid te bepaal. Die effek van die intervensie is oor drie fases, wat elk bestaan het uit vier weke, evalueer. Gedurende die fases, kon die deelnemer met haar gewone rekenaarwerk voortgaan. Die resultate is saamgestel en getabuleer. Resultate: Daar was ‘n vemindering in die intensiteit van nekpyn, boonste rug pyn en die sitgemak van die individu het ook verbeter. Hierdie verbeteringe was egter nie statisties of klinies betekenisvol nie. Die effek grootte vir pyn intensiteit was 0.76 en vir sitgemak was 0.21. Die deelnemer het geen gestremdheid gerapporteer, soos gemeet met die NOI met aanvangs van die studie of teen die einde van die studie nie. Gevolgtrekking: Die vertikale hoogte-aanpassing van die stoel en beeldskerm van hierdie vroulike rekenaar werker volgens haar antropometrie het bygedra tot ‘n verbetering in nek en boonste rug pyn, asook sitgemak. Hierdie ergonomiese werkstasie intervensie kan deel vorm van die praktiese hantering van nek en boonste rug pyn in rekenaargebruikers. Verdere navorsing wod aanbeveel om te bepaal of hierdie bevindinge veralgemeenbaar is na die wyer gemeenskap van rekenaarverbruikers.

A dissertation 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 Master of Science in Engineering. Johannesburg, 2015 / This research investigates the e ects of the frequency components of the lightning First Short Stroke (FSS) on the current pathway through human tissues using frequency domain analysis. A Double Exponential Function (DEF) is developed to model the FSS with frequency components in the range 10 Hz 100 kHz. Human tissues are simulated using Finite Element Analysis (FEA) in COMSOL and comprises of two types of models: Single Layer Cylindrical Model (SLCM) and Multi-layered Cylindrical Model (MLCM). The SLCM models 54 human tissues independently and the MLCM models the human leg with ve tissue layers: bone marrow, cortical bone, muscle, blood and fat. Three aspects are analysed: current density, complex impedance and power dissipation. From the SLCM results, aqueous tissues have the lowest impedances and tissue heat dissipation is proportional to tissue impedance. Results from the MLCM show that 85% of the FSS current ows through muscle, 11% ows through blood, 3:5% through fat and the rest through cortical bone and bone marrow. From the results, frequency dependent equivalent circuit models consisting of resistors and capacitors connected in series are proposed. The simulation results are correlated with three main clinical symptoms of lightning injuries: neurological, cardiovascular and external burns. The results of this work are applicable to the analysis of High Voltage (HV) injuries at power frequencies. / MT2017

Resumo: Os altos índices de tecnificação da mecanização agrícola e o largo emprego desta nas propriedades rurais, têm levado ao campo problemas que antes eram restritos às áreas industriais, que são as doenças profissionais e os acidentes, causando aumentos de gastos, perda de eficiência, afastamentos temporários e definitivos. Toda interrupção neste processo produtivo, acarreta perda de competitividade. O objetivo principal deste estudo, foi a avaliação das principais fontes de ruídos em pulverizadores costais motorizados, analisando-os pelo prisma da Ergonomia e da Segurança do Trabalho, através da aplicação de normas nacionais (ABNT,NR12 e NR15) e internacionais (ISO). Foram utilizados para este estudo três pulverizadores, que foram ensaiados e os resultados comparados com o limite máximo de exposição estabelecido pela norma. Os níveis máximos apurados para os três aparelhos, proximo ao ouvido do operador foram respectivamente: 96 dB(A), 96,88 dB(A) e 95,88 dB(A). O levantamento dos níveis de vibração foram realizados à título preliminar somente em um dos aparelhos e servirão de base para estudos posteriores. Foram obtidas nos testes do operador com o aparelho, acelerações de 34,87 m/sø. O que foi concluído com a confrontação destes dados, é que os níveis de ruído e vibração produzidos, encontram-se bem acima dos parâmetros normalizados, podendo provocar danos auditivos e não auditivos. Concluiu-se também que as vibrações merecem um estudo posterior, mais aprofundado. Os resultados confirmaram as expectativas, demonstrando a inadaptabilidade dos pulverizadores estudados ao organismo humano e podem servir de base para futuros estudos e correções nestes equipamentos. / Abstract: The high indexes of technicality of agricultural mechanization and the wide use of it in rural properties have taken to the field problems which had been formerly restricted to industrial areas, which are the professional diseases and accidents, bringing about increase of expenses, loss of efficiency, temporary and definitive leaves. Every interruption in this productive process causes loss of competitiveness. The main purpose of this study has been the evaluation of the main sources of noise in motorized knapsacks, analyzing them through the prism of Ergonomics and Work Security, by means of national norms (ABNT, NR12, NR15) and international norms (ISO). For this study, three knapsacks were utilized, being rehearsed and the results compared to the maximum limit of exposition established by the norm. Maximum levels achieved for the three engines next to the operator's ear were, respectively, 96 dB (A), 96,88 dB(A) and 95,88 dB(A). The survey about the vibration levels was accomplished on preliminary purpose only on one of the engines and will serve as base for future studies. Accelerations of 34,87 m/s2 were obtained on the operator's tests with the engine. Was been concluded through confrontation of these data is that the noise and vibration levels produced are found distantly above the normalized parameters and may trigger auditive and non-auditive damage. It also follows that the vibrations deserve a future and more profound study. The results confirmed the expectancies, demonstrating the inadaptability of the studied knapsacks to human organism and may serve as base for future studies and corrections in this equipment. / Orientador: Marcos Roberto Bormio / Coorientador: João Eduardo Guarnetti dos Santos / Banca: Gastão Moraes da Silveira / Banca: João Candido Fernandes / Mestre

Este trabalho propõe um novo conceito de cadeira de rodas manual ergonômica com assistência motorizada servo controlada. A mobilidade em cadeira propulsionada manualmente é uma das formas mais utilizadas de locomoção entre pessoas com deficiências, porém expõe o usuário ao risco de lesão nos membros superiores e não propicia independência em todas as situações de locomoção diária. A primeira alternativa tecnológica aplicada pelo homem foi a motorização. No entanto, o uso desta não implica em melhora da mobilidade, pois leva o usuário ao sedentarismo. Neste sentido, fazendo a integração do histórico, ergonomia, biomecânica e engenharia mecatrônica, este projeto tem como objetivo o desenvolvimento do projeto conceitual ao protótipo - de uma cadeira de rodas manual com assistência motorizada complementar e proporcional à força propulsora aplicada pelo usuário. O delineamento do projeto envolveu o levantamento das evidências científicas relacionadas aos aspectos da configuração de cadeiras manuais determinantes para a melhoria do desempenho na mobilidade e conforto. A criação do conceito envolveu ainda a realização de estudos complementares dos aspectos mecânicos, ergonômicos e cinemáticos da locomoção em cadeiras manuais. O conceito do protótipo tem seus pilares na: propulsão, através de um servo-motor centralizado que atua nas duas rodas traseiras através de um diferencial mecânico, simplificando o controle da assistência motorizada; no projeto do aro propulsor ortogonal com acoplamento assimétrico com a roda em cambagem, proporcionando melhor acesso das mãos ao aro; projeto do aro propulsor, baseado em aspectos dactilo-anatômicos; projeto e configuração da cadeira, estruturada nas evoluções tecnológicas das cadeiras manuais e adaptada às características antropométricas da população brasileira; assistência motorizada controlada por um sistema de avaliação contínua da inclinação do terreno, forças aplicadas ao aro e o deslocamento angular das rodas medidos por acelerômetro, células de carga e encoder ótico, respectivamente. A efetivação do presente conceito favorece a mobilidade independente do cadeirante, podendo reduzir o custo referente ao uso prolongado de cadeiras manuais: lesão dos membros superiores e incapacidade funcional. Aprimorar a mobilidade de usuários de cadeira de rodas favorece sua independência e participação social, aspectos essenciais para a melhora da qualidade de vida. / This study proposes a new concept of ergonomic manual wheelchair with servo-controlled motor assistance. The mobility in manually propelled wheelchairs is one of the most used means of locomotion among people with disabilities, but it exposes the users to the risk of upper limb injuries and does not provide independence in all the situations of daily locomotion. The first solution applied was the use of a electric-powered motors. However, its usage does not lead to an improvement in mobility and imposes the sedentary condition to the users. Thus, by integrating of the equipment history, ergonomics, biomechanics and mechatronics engineering, this project aims to develop - from the conceptual design to the prototype - a manual wheelchair with complementary motorized assistance that is proportional to the pushing force applied by the user. The project design involved the search for scientific evidences related to the aspects of the wheelchair configuration determinants for the improvement on mobility performance and comfort. The concept creation also involved complementary studies of the mechanics, ergonomics and kinematics of manual wheelchair mobility. The fundamentals of the equipment conception are: propulsion by a servo-motor centrally located that operates the rear wheels by differential transmission. thus simplifying the motor assistance control; the design of an orthogonal handrim coupled to the a cambered wheel, that provides better access of the hands to the rim; the dactyl-anatomical design of the handrim; the wheelchair configuration designed based on the technological evolution of the manual wheelchairs and anthropometric features of the Brazilian population; motor assistance controlled by a system with real-time assessment of the ground slope, handrim forces and angular displacement of the wheels measured, respectively, by accelerometer, load cells and optical encoder. This concept favors the independent mobility of the users and may reduce the cost related to the long term use of manual wheelchairs: upper limb injuries and functional impairment. Improving the mobility of wheelchair users favors their independence and social participation, two essential aspects for the improvement in quality of life.

Emotional design addresses peoples needs and desires which is at the center of product or technology development. Currently, there is no established process of emotional design in the field of industrial design to address research and design issues. A five step emotional design process is proposed in this thesis. Research theories and methods on emotional design were reviewed. Existing pantry storage products were evaluated. User research was targeted on women between age 45 and 60. Research data were collected through interviews and surveys. Research findings were produced by analyzing the data using a proposed data analysis method called Product Emotion Baseline. Product function design, product interface design and user experience study on smart pantry were presented. All five steps of emotional design process were applied to smart pantry design to illustrate in detail how the proposed process works.

The appearance of the electrical appliances has undergone a dramatic change in many aspects since the 1920&rsquo / s. Throughout years, along with their changed appearance, the way the appliances are perceived has altered. The interface of domestic products is mainly dominated by visual elements. Undoubtedly, the domination of the visual perception in the interfaces of the appliances might cause complications in the interaction between the product and visually impaired users. In this thesis, the interaction between the electrical household appliances and visually impaired user is examined to identify the strong points in the interaction as well as any complications that may occur during the interaction. Observations were conducted with ten users to explore the interaction between the visually impaired users and three electrical domestic appliances: washing machine, vacuum cleaner and iron. The findings of the observations indicate that visually impaired users can operate their appliances, with some limitations. Yet a number of common problematic points related to the interface elements, which hinder from using their electrical appliances with full functionality, were encountered. At the end of the study, a list of design recommendations, some of which offered in the literature previously, are suggested.

In this thesis, we consider the Multi Resource Agent Bottleneck Generalized Assignment Problem. We aim to minimize the maximum load over all agents. We study the Linear Programming (LP) relaxation of the problem. We use the optimal LP relaxation solutions in our Branch and Bound algorithm while defining lower and upper bounds and branching schemes. We find that our Branch and Bound algorithm returns optimal solutions to the problems with up to 60 jobs when the number of agents is 5, and up to 30 jobs when the number of agents is 10, in less than 20 minutes. To find approximate solutions, we define a tabu search algorithm and an &amp / #945 / approximation algorithm. Our computational results have revealed that these procedures can find high quality solutions to large sized instances very quickly.

No description available.

Diss. (sammanfattning) Umeå : Univ., 2004. / Härtill 6 uppsatser.

Thesis (Dr. P.H.)--University of Texas Health Science Center at Houston, School of Public Health, 1993. / Typescript. Includes bibliographical references (leaves 105-110).