57 research outputs found

    On the Mental Workload Assessment of Uplift Mapping Representations in Linked Data

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    Self-reporting procedures have been largely employed in literature to measure the mental workload experienced by users when executing a specific task. This research proposes the adoption of these mental workload assessment techniques to the task of creating uplift mappings in Linked Data. A user study has been performed to compare the mental workload of “manually” creating such mappings, using a formal mapping language and a text editor, to the use of a visual representation, based on the block metaphor, that generate these mappings. Two subjective mental workload instruments, namely the NASA Task Load Index and the Workload Profile, were applied in this study. Preliminary results show the reliability of these instruments in measuring the perceived mental workload for the task of creating uplift mappings. Results also indicate that participants using the visual representation achieved smaller and more consistent scores of mental workload

    Current socio-economic measures, and not those measured during infancy, affect bone mass in poor urban South african children.

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    Understanding the impact of socio-economic status (SES) on physical development in children is important, especially in developing countries where considerable inequalities persist. This is the first study to examine the association between SES on bone development at the whole body, femoral neck, and lumbar spine in black children living in Soweto and Johannesburg, South Africa. Linear regression models were used to study associations between SES during infancy and current SES, anthropometric, and DXA-derived bone mass in 9/10-yr-old children (n = 309). Findings suggest that current SES measures, rather than SES during infancy, are stronger predictors of current whole body bone area (BA) and whole body BMC after adjusting for body size, pubertal development, physical activity, habitual dietary calcium intake, and body composition. SES had no significant effect on either hip or spine bone mass. Caregiver's marital/cohabiting status (indicator of social support) and whether there was a television in the home (indicator of greater income) at age 9/10 yr were the most important socio-economic determinants of whole body BA and BMC. SES has a significant independent effect on whole body BMC through its impact on BA. This suggests that poverty alleviation policies in South Africa could have a positive effect on bone health

    A Multilevel Approach to Relating Subjective Workload to Performance After Shifts in Task Demand

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    Objective: The aim of this laboratory experiment was to demonstrate how taking a longitudinal, multilevel approach can be used to examine the dynamic relationship between subjective workload and performance over a given period of activity involving shifts in task demand.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline

    Taking a Closer Look at Flight Crew Handling of Complex Failures: Ten Case Studies

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    Non-normal events, in particular system failures with serious operational impact are rare in flight operations. These events are not always easy to handle by flight crews. The aim of the performed study is to determine where in this process potential issues may lie. Ten incident reports are studied using a newly developed operational issue analysis framework. The framework is used to determine whether and how the current interfaces communicate the initial functional impact and functional impact delayed in time. Additionally, results from pilot interviews are presented which identified three phases of non-normal event handling: fault detection, fault management and strategic planning. Analysis of the ten cases shows that current alert systems are mainly supporting the first two phases while the strategic planning phase, requiring higher level functional information integrated into the operational context as well as failure impact later in time, is relying almost entirely on pilot knowledge and reasoning

    The effect of surprise on upset recovery performance

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    Introducing the element of surprise is one of the main challenges in simulator training of in-flight emergencies. In this simulator study, we investigated the differences in performance between predictable and surprising circumstances, in order to obtain insight into the transfer of training between predictable training settings and surprising circumstances in operational practice. This was done by testing twenty airline pilots who recovered from an aerodynamic stall in two conditions: one anticipation condition and one surprise condition. All pilots practiced beforehand using predictable, or nonsurprising scenarios. The results show that pilots had significantly more difficulties in adhering to components of the FAA-commissioned recovery template in the surprise condition compared to the anticipation condition. These results suggest that predictable training may not be enough to prevent serious performance decrements under surprise
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