2,553 research outputs found

    A Universalist strategy for the design of Assistive Technology

    Get PDF
    Assistive Technologies are specialized products aiming to partly compensate for the loss of autonomy experienced by disabled people. Because they address special needs in a highly-segmented market, they are often considered as niche products. To improve their design and make them tend to Universality, we propose the EMFASIS framework (Extended Modularity, Functional Accessibility, and Social Integration Strategy). We first elaborate on how this strategy conciliates niche and Universalist views, which may appear conflicting at first sight. We then present three examples illustrating its application for designing Assistive Technologies: the design of an overbed table, an upper-limb powered orthose and a powered wheelchair. We conclude on the expected outcomes of our strategy for the social integration and participation of disabled people

    Correction: Modelling Influence and Opinion Evolution in Online Collective Behaviour.

    Get PDF
    [This corrects the article DOI: 10.1371/journal.pone.0157685.]

    Aerodrome Flight Information Service

    Get PDF
    The objective of this article is to describe aerodrome flight information service and activities provided by AFIS officer and also highlight potential improvements

    Reports about Occurrence of Events with Effect on Aviation Safety

    Get PDF
    This article deals with a system, that is established to report the events with effect on safety. This system is based on requirements published in Annex 13 to the Chicago Convention and legislative foundations laid down in Regulation L13, Regulation of the European Parliament and of the Council (EU) No 376/2014, Decree No. 359/2006 Sb. and Act No. 49/1997 Sb. Standards and legislative rules precisely define the types of events that are subject of reporting and also define the structure and content of the reporting message. This content is consists mainly of the identification data about the airplane and crew, information about the route and a short description of the damage to the airplane. In the following, we discuss the possible use of such a system of mandatory reporting for the needs of safety indicators. Then there are proposals of changes in the content of the reporting message for the need of safety indicators. The present knowledge indicates that the use of all opportunities provided by the law for the reporting of events can lead to a creating of sufficient basis for safety indicators

    Cell-by-Cell Dissection of Gene Expression and Chromosomal Interactions Reveals Consequences of Nuclear Reorganization

    Get PDF
    The functional consequences of long-range nuclear reorganization were studied in a cell-by-cell analysis of gene expression and long-range chromosomal interactions in the Drosophila eye and eye imaginal disk. Position-effect variegation was used to stochastically perturb gene expression and probe nuclear reorganization. Variegating genes on rearrangements of Chromosomes X, 2, and 3 were probed for long-range interactions with heterochromatin. Studies were conducted only in tissues known to express the variegating genes. Nuclear structure was revealed by fluorescence in situ hybridization with probes to the variegating gene and heterochromatin. Gene expression was determined alternately by immunofluorescence against specific proteins and by eye pigment autofluorescence. This allowed cell-by-cell comparisons of nuclear architecture between cells in which the variegating gene was either expressed or silenced. Very strong correlations between heterochromatic association and silencing were found. Expressing cells showed a broad distribution of distances between variegating genes and their own centromeric heterochromatin, while silenced cells showed a very tight distribution centered around very short distances, consistent with interaction between the silenced genes and heterochromatin. Spatial and temporal analysis of interactions with heterochromatin indicated that variegating genes primarily associate with heterochromatin in cells that have exited the cell cycle. Differentiation was not a requirement for association, and no differences in association were observed between cell types. Thus, long-range interactions between distal chromosome regions and their own heterochromatin have functional consequences for the organism

    Non-linear finite-element analysis of the shear response in prestressed concrete bridges

    Get PDF
    For the structural assessment of concrete bridges, the non-linear finite-element method has become an important and increasingly used tool. The method has shown a great potential to reveal higher load-carrying capacity compared with conventional assessment methods. However, the modelling method used for reinforced and prestressed concrete members subjected to shear and torsion has been questioned. The aim of this study is to present an analysis method for evaluation of the load-carrying capacity of prestressed concrete bridges, when failure resulting from shear and torsion is the main problem. The modelling method used was previously worked out and verified for shear-type cracking and shear failure. Here, shell elements with embedded reinforcement were used together with non-linear material models, taking into account the fracture energy of cracking plain concrete and the reduction of the concrete compression strength owing to lateral tensile strain. Analyses with the method proposed have shown to predict the shear response and the shear capacity on the safe side. In the work presented here, the load-carrying capacity of a box-girder bridge was evaluated as a case study. The whole bridge was modelled, but only the part that was most critical to shear and torsion was modelled according to the method previously worked out and was combined with beam elements for the rest of the bridge. The case study showed a substantially higher load-carrying capacity for the bridge compared with the assessment with conventional methods. In the evaluation, several possible safety formats were used in combination with the non-linear finite-element method. It was shown that the format using partial safety factors gave unrealistic conservative results; it is more correct to use the semi-probabilistic formats for non-linear finite-element analysis. \ua9 2009 Thomas Telford Ltd

    Pre-study of Dynamic Amplification Factor for Existing Road Bridges

    Get PDF
    The Swedish Road network has, since 2018, been divided into four bearing capacity classes (BKs)—BK1–BK4. The heaviest allowed gross vehicle weight increased when BK4 was introduced, from 64 tonnes (BK1) to 74 tonnes (BK4). The Swedish Transport Administration aims, by 2025, to classify 60 % of the strategic road network for the heavy transport industry as BK4, increasing to 70–80 % by 2029. However, to reach these goals, it is estimated that over 700 bridges will need to be strengthened or replaced.This study, using a site-specific investigation to calculate the assessment dynamic ratio (ADR), showed that some of these bridges could be upgraded to BK4. A review of the literature indicated that light vehicles tend to have high dynamic amplification factors (DAFs), but light vehicles do not have critical load effects and are therefore not relevant from a design perspective. Instead, heavy vehicles are critical for the design. Both experimental and analytical investigations have shown that heavy gross vehicle weights result in low DAF values.This report proposes effective ways to collect site-specific dynamic traffic load information and a methodology to produce site-specific dynamic allowances using both experimental measurements and numeric models. It also explains how this methodology can be adopted by transportation agencies to study bridges along transport corridors.Findings from the pre-study have resulted in the following research proposals: sitespecific field measurements to quantify DAFs, guidelines for numerical modelling of vehicle–bridge interactions (VBIs), DAF for each limit state, three–dimensional analysis of VBIs, the introduction of gross vehicle weight into DAF equations, and pilot tests of proposed frameworks for transport corridors. The authors believe that several topics can be covered within the framework of a PhD project

    Combined effects of UV-B and drought on native and exotic populations of Verbascum thapsus L.

    Get PDF
    During plant invasions, exotic species have to face new environmental challenges and are affected by interacting components of global change, which may include more stressful environmental conditions. We investigated an invasive species of New Zealand grasslands, commonly exposed to two concomitant and limiting abiotic factors—high levels of ultraviolet-B radiation and drought. The extent to which Verbascum thapsus may respond to these interacting stress factors via adaptive responses was assessed in a greenhouse experiment comprising native German plants and plants of exotic New Zealand origins. Plants from both origins were grown within four treatments resulting from the crossed combinations of two levels of UV-B and drought. Over twelve weeks, we recorded growth, morphological characteristics, physiological responses and productivity. The results showed that drought stress had the strongest effect on biomass, morphology and physiology. Significant effects of UV-B radiation were restricted to variables of leaf morphology and physiology. We found neither evidence for additive effects of UV-B and drought nor origin-dependent stress responses that would indicate local adaptation of native or exotic populations. We conclude that drought-resistant plant species might be predisposed to handle high UV-B levels, but emphasize the importance of setting comparable magnitudes in stress levels when testing experimentally for antagonistic interaction effects between two manipulated factors
    corecore