5,168 research outputs found

    "I always know what's going on." Assessing the Relationship between Perceived and Actual Situation Awareness across Different Scenarios

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    Effective performance in a situation relies on having a good awareness of that situation or at least, if SA is poor, being aware that this is the case. This study examined the bias (tendency to accept or reject available information) and actual and perceived SA of firefighters across two different situations The data suggested that, although actual SA and bia varied across the situations, perceived SA remained relatively constant. This raises the possibility that individuals may have a ‘resting level’ of perceived SA and that the tasks used in this study were effective in manipulating actual SA while perceived SA remained at the resting level

    "I always know what's going on." Assessing the Relationship between Perceived and Actual Situation Awareness across Different Scenarios

    Get PDF
    Effective performance in a situation relies on having a good awareness of that situation or at least, if SA is poor, being aware that this is the case. This study examined the bias (tendency to accept or reject available information) and actual and perceived SA of firefighters across two different situations The data suggested that, although actual SA and bia varied across the situations, perceived SA remained relatively constant. This raises the possibility that individuals may have a ‘resting level’ of perceived SA and that the tasks used in this study were effective in manipulating actual SA while perceived SA remained at the resting level

    The human brain in fireground decision-making: trustworthy firefighting equipment?

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    The research programme to date has involved studies of the response of Fire and Rescue (FRS) crew and commanders in fireground training situations and simulations (tabletop, BA and incident command exercises). The studies have revealed patterns and tendencies with potentially serious consequences for real FRS situations. The main conclusion from these studies is that the fire personnel involved were well-trained professionals with good “Situation Awareness” (SA) or knowledge of the incident under study, but there was also evidence of “bias” in decision-making leading to either a tunneling or broadening of focus that may respectively produce “miss” or “false alarm” errors. This tendency is linked to the limits of the human brain under pressure and could explain tragic errors of decision-making such as may have occurred in real-life fire incidents

    Glaucoma Home Monitoring Using a Tablet- Based Visual Field Test (Eyecatcher): An Assessment of Accuracy and Adherence Over 6 Months

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    PURPOSE: To assess accuracy and adherence of visual field (VF) home monitoring in a pilot sample of patients with glaucoma. DESIGN: Prospective longitudinal feasibility and reliability study. METHODS: Twenty adults (median 71 years) with an established diagnosis of glaucoma were issued a tablet perimeter (Eyecatcher) and were asked to perform 1 VF home assessment per eye, per month, for 6 months (12 tests total). Before and after home monitoring, 2 VF assessments were performed in clinic using standard automated perimetry (4 tests total, per eye). RESULTS: All 20 participants could perform monthly home monitoring, though 1 participant stopped after 4 months (adherence: 98% of tests). There was good concordance between VFs measured at home and in the clinic (r = 0.94, P < .001). In 21 of 236 tests (9%), mean deviation deviated by more than ±3 dB from the median. Many of these anomalous tests could be identified by applying machine learning techniques to recordings from the tablets' front-facing camera (area under the receiver operating characteristic curve = 0.78). Adding home-monitoring data to 2 standard automated perimetry tests made 6 months apart reduced measurement error (between-test measurement variability) in 97% of eyes, with mean absolute error more than halving in 90% of eyes. Median test duration was 4.5 minutes (quartiles: 3.9-5.2 minutes). Substantial variations in ambient illumination had no observable effect on VF measurements (r = 0.07, P = .320). CONCLUSIONS: Home monitoring of VFs is viable for some patients and may provide clinically useful data

    Capacity fade in nickel cadmium and nickel hydrogen cells

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    Research and operational experience with capacity fade in nickel cadmium and nickel hydrogen cells are summarized in outline form. The theoretical causes of capacity fade are reviewed and the role of cell storage, positive electrodes, and cobalt additives are addressed. Three examples of observed capacity fade are discussed: INTELSAT 5, INTELSAT 6, and an Explorer platform. Finally, prevention and recovery methods are addressed and the current status of Eagle Picher/Hughes research is discussed

    Estimation and resolution of heat capacities: Lattice heat capacity morphology

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    To utilize heat capacity determinations in the chemical thermodynamic region effectively, it is essential to be able to resolve the "excess" contributions, be they electronic (e.g. Schottky), magnetic, order--disorder, or one of the named transitions (Anderson, Verwey, etc.), from the often predominant lattice heat capacity. This paper addresses recent developments in bridging the experimental/utilization gap and compares the recent high precision approaches with each other and with experimental work on homologous series and selected substances.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/31259/1/0000165.pd

    The Human Touch:Using a Webcam to Autonomously Monitor Compliance During Visual Field Assessments

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    Purpose: To explore the feasibility of using various easy-to-obtain biomarkers to monitor non-compliance (measurement error) during visual field assessments. Methods: Forty-two healthy adults (42 eyes) and seven glaucoma patients (14 eyes) underwent two same-day visual field assessments. An ordinary webcam was used to compute seven potential biomarkers of task compliance, based primarily on eye gaze, head pose, and facial expression. We quantified the association between each biomarker and measurement error, as defined by (1) test-retest differences in overall test scores (mean sensitivity), and (2) failures to respond to visible stimuli on individual trials (stimuli -3 dB or more brighter than threshold). Results: In healthy eyes, three of the seven biomarkers were significantly associated with overall (test-retest) measurement error (P = 0.003-0.007), and at least two others exhibited possible trends (P = 0.052-0.060). The weighted linear sum of all seven biomarkers was associated with overall measurement error, in both healthy eyes (r = 0.51, P <0.001) and patients (r = 0.65, P <0.001). Five biomarkers were each associated with failures to respond to visible stimuli on individual trials (all P <0.001). Conclusions: Inexpensive, autonomous measures of task compliance are associated with measurement error in visual field assessments, in terms of both the overall reliability of a test and failures to respond on particular trials ("lapses"). This could be helpful for identifying low-quality assessments and for improving assessment techniques (e.g., by discounting suspect responses or by automatically triggering comfort breaks or encouragement). Translational Relevance: This study explores a potential way of improving the reliability of visual field assessments, a crucial but notoriously unreliable clinical measure

    Acceptability of a home-based visual field test (Eyecatcher) for glaucoma home monitoring: a qualitative study of patients' views and experiences

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    Objectives To explore the acceptability of home visual field (VF) testing using Eyecatcher among people with glaucoma participating in a 6-month home monitoring pilot study. Design Qualitative study using face-to-face semistructured interviews. Transcripts were analysed using thematic analysis. Setting Participants were recruited in the UK through an advertisement in the International Glaucoma Association (now Glaucoma UK) newsletter. Participants Twenty adults (10 women; median age: 71 years) with a diagnosis of glaucoma were recruited (including open angle and normal tension glaucoma; mean deviation=2.5 to -29.9 dB). Results All participants could successfully perform VF testing at home. Interview data were coded into four overarching themes regarding experiences of undertaking VF home monitoring and attitudes towards its wider implementation in healthcare: (1) comparisons between Eyecatcher and Humphrey Field Analyser (HFA); (2) capability using Eyecatcher; (3) practicalities for effective wider scale implementation; (4) motivations for home monitoring. Conclusions Participants identified a broad range of benefits to VF home monitoring and discussed areas for service improvement. Eyecatcher was compared positively with conventional VF testing using HFA. Home monitoring may be acceptable to at least a subset of people with glaucoma
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