96 research outputs found

    Human Arm simulation for interactive constrained environment design

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    During the conceptual and prototype design stage of an industrial product, it is crucial to take assembly/disassembly and maintenance operations in advance. A well-designed system should enable relatively easy access of operating manipulators in the constrained environment and reduce musculoskeletal disorder risks for those manual handling operations. Trajectory planning comes up as an important issue for those assembly and maintenance operations under a constrained environment, since it determines the accessibility and the other ergonomics issues, such as muscle effort and its related fatigue. In this paper, a customer-oriented interactive approach is proposed to partially solve ergonomic related issues encountered during the design stage under a constrained system for the operator's convenience. Based on a single objective optimization method, trajectory planning for different operators could be generated automatically. Meanwhile, a motion capture based method assists the operator to guide the trajectory planning interactively when either a local minimum is encountered within the single objective optimization or the operator prefers guiding the virtual human manually. Besides that, a physical engine is integrated into this approach to provide physically realistic simulation in real time manner, so that collision free path and related dynamic information could be computed to determine further muscle fatigue and accessibility of a product designComment: International Journal on Interactive Design and Manufacturing (IJIDeM) (2012) 1-12. arXiv admin note: substantial text overlap with arXiv:1012.432

    A heat-and-pull rig for fiber taper fabrication

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    We describe a reproducible method of fabricating adiabatic tapers with 3-4 micron diameter. The method is based on a heat-and-pull rig, whereby a CO2 laser is continuously scanned across a length of fiber that is being pulled synchronously. Our system relies on a CO2 mirror mounted on a geared stepper motor in order to scan the laser beam across the taper region. We show that this system offers a reliable alternative to more traditional rigs incorporating galvanometer scanners. We have routinely obtained transmission losses between 0.1 and 0.3 dB indicating the satisfactory production of adiabatic tapers. The operation of the rig is described in detail and an analysis on the produced tapers is provided. The flexibility of the rig is demonstrated by fabricating prolate dielectric microresonators using a microtapering technique. Such a rig is of interest to a range of fields that require tapered fiber fabrication such as microcavity-taper coupling, atom guiding along a tapered fiber, optical fiber sensing and the fabrication of fused biconical tapered couplers.Comment: 13 pages, 6 figures Submitted to Rev. Sci. Instru

    Characterization of the N-glycans of female Angiostrongylus cantonensis worms

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    Glycoconjugates play a crucial role in the host-parasite relationships of helminthic infections, including angiostrongyliasis. It has previously been shown that the antigenicity of proteins from female Angiostrongylus cantonensis worms may depend on their associated glycan moieties. Here, an N-glycan profile of A. cantonensis is reported. A total soluble extract (TE) was prepared from female A. cantonensis worms and was tested by western blot before and after glycan oxidation or N- and O-glycosidase treatment. The importance of N-glycans for the immunogenicity of A. cantonensis was demonstrated when deglycosylation of the TE with PNGase F completely abrogated IgG recognition. The TE was also fractionated using various lectin columns [Ulex europaeus (UEA), concanavalin A (Con A), Arachis hypogaea (PNA), Triticum vulgaris (WGA) and Lycopersicon esculentum (LEA)], and then each fraction was digested with PNGase F. Released N-glycans were analyzed with matrix-assisted laser desorption ionization (MALDI)-time-of-flight (TOF)-mass spectrometry (MS) and MALDI-TOF/TOF-MS/MS. Complex-type, high mannose, and truncated glycan structures were identified in all five fractions. Sequential MALDI-TOF-TOF analysis of the major MS peaks identified complex-type structures, with a α1-6 fucosylated core and truncated antennas. Glycoproteins in the TE were labeled with BodipyAF558-SE dye for a lectin microarray analysis. Fluorescent images were analyzed with ProScanArray imaging software followed by statistical analysis. A total of 29 lectins showed positive binding to the TE. Of these, Bandeiraea simplicifolia (BS-I), PNA, and Wisteria floribunda (WFA), which recognize galactose (Gal) and N-acetylgalactosamine (GalNAc), exhibited high affinity binding. Taken together, our findings demonstrate that female A. cantonensis worms have characteristic helminth N-glycans.Office of the Snr Dep Vice Chancellor, Institute for GlycomicsNo Full Tex

    A method to design job rotation schedules to prevent work-related musculoskeletal disorders in repetitive work

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    This is an Accepted Manuscript of an article published by Taylor & Francis Group in International Journal of Production Research in 2012, available online: http://www.tandfonline.com/10.1080/00207543.2011.653452.Job rotation is an organisational strategy widely used in human-based production lines with the aim of preventing work-related musculoskeletal disorders (WMSDs). These work environments are characterised by the presence of a high repetition of movements, which is a major risk factor associated with WMSDs. This article presents a genetic algorithm to obtain rotation schedules aimed at preventing WMSDs in such environments. To do this, it combines the effectiveness of genetic algorithms optimisation with the ability to evaluate the presence of risk by repeated movements by following the OCRA ergonomic assessment method. The proposed algorithm can design solutions in which workers will switch jobs with high repeatability of movements with other less demanding jobs that support their recovery. In addition, these solutions are able to diversify the tasks performed by workers during the day, consider their disabilities and comply with restrictions arising from the work organisation.The authors wish to thank the Universitat Politecnica de Valencia which supported this research through its Program for the Support of Research and Development 2009 and its financing through the project PAID-06-09/2902.Asensio Cuesta, S.; Diego-Mas, JA.; Cremades Oliver, L.; González-Cruz, M. (2012). A method to design job rotation schedules to prevent work-related musculoskeletal disorders in repetitive work. International Journal of Production Research. 50(24):7467-7478. https://doi.org/10.1080/00207543.2011.653452S74677478502

    Identificação dos riscos de distúrbios ocupacionais em uma microempresa de confecção: contribuições da terapia ocupacional

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    Occupational disorders are pathologies with cumulative trauma and slow and progressive evolution, linked to occupational activities performed and/or working conditions. Such, based on the increasing number of occupational disorders in the confection branch, this study aims to identify risks of occupational disorders in a small group of seamstresses in the interior of Paraíba, and also point contributions of occupational therapy in view of the well-being these subjects in their work environment, preventing possible illnesses resulting from their work activities affecting performance in their daily occupations. As a means of evaluation we used the body map, pain scale, self-administered questionnaire professional sociodemographic and a observation script of systematic ergonomic direct and indirect, that have been applied/performed with these seamstresses. Data from these instruments were coded for the realization of individual and/or collective orientations of a preventive nature and aiming the well-being of these individuals in their working environment to not affect other occupations that may be significant.Distúrbios ocupacionais são as patologias com traumas cumulativos e de evolução lenta e progressiva, vinculadas às atividades ocupacionais desempenhadas e/ou às condições de trabalho. Assim, tendo como base o crescente aumento de distúrbios ocupacionais no ramo da confecção, o presente estudo visa identificar riscos de distúrbios ocupacionais em um pequeno grupo de costureiras no interior da Paraíba, e também apontar contribuições da Terapia Ocupacional tendo em vista o bem-estar desses sujeitos em seu ambiente de trabalho, evitando possíveis adoecimentos decorrentes de suas atividades laborais que afetem o desempenho em suas ocupações diárias. Como forma de avaliação foi utilizado o mapa corporal, escala de dor, questionário sócio demográfico profissional autoaplicável e um roteiro de observação ergonômico sistemático direto e indireto, que foram aplicados/realizados com as referidas costureiras. Os dados provenientes desses instrumentos foram codificados para a realização das orientações individuais e/ou coletivas de cunho preventivo e objetivando o bem-estar desses indivíduos em seu contexto de trabalho para não afetar outras ocupações que lhes sejam significativas

    Pooling job physical exposure data from multiple independent studies in a consortium study of carpal tunnel syndrome

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    Pooling data from different epidemiological studies of musculoskeletal disorders (MSDs) is necessary to improve statistical power and to more precisely quantify exposure–response relationships for MSDs. The pooling process is difficult and time-consuming, and small methodological differences could lead to different exposure–response relationships. A subcommittee of a six-study research consortium studying carpal tunnel syndrome: (i) visited each study site, (ii) documented methods used to collect physical exposure data and (iii) determined compatibility of exposure variables across studies. Certain measures of force, frequency of exertion and duty cycle were collected by all studies and were largely compatible. A portion of studies had detailed data to investigate simultaneous combinations of force, frequency and duration of exertions. Limited compatibility was found for hand/wrist posture. Only two studies could calculate compatible Strain Index scores, but Threshold Limit Value for Hand Activity Level could be determined for all studies. Challenges of pooling data, resources required and recommendations for future researchers are discussed
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