The paper presents a framework that through structured analysis of accident reports explores the differences between practice and academic literature as well amongst organizations regarding their views on human error. The framework is based on the hypothesis that the wording of accident reports reflects the safety thinking and models that have been applied during the investigation, and includes 10 aspects identified in the state-of-the-art literature. The framework was applied to 52 air accident reports published by the Dutch Safety Board (DSB) and 45 ones issued by the Australian Transport Safety Bureau (ATSB) from 1999 to 2014. Frequency analysis and statistical tests showed that the presence of the aspects in the accident reports varied from 32.6% to 81.7%, and revealed differences between the ATSB and the DSB approaches to human error. However, in overall safety thinking have not changed over time, thus, suggesting that academic propositions might have not yet affected practice dramatically.
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Background To gain insight into the role of plantar intrinsic foot muscles in fall-related gait parameters in older adults, it is fundamental to assess foot muscles separately. Ultrasonography is considered a promising instrument to quantify the strength capacity of individual muscles by assessing their morphology. The main goal of this study was to investigate the intra-assessor reliability and measurement error for ultrasound measures for the morphology of selected foot muscles and the plantar fascia in older adults using a tablet-based device. The secondary aim was to compare the measurement error between older and younger adults and between two different ultrasound machines. Methods Ultrasound images of selected foot muscles and the plantar fascia were collected in younger and older adults by a single operator, intensively trained in scanning the foot muscles, on two occasions, 1–8 days apart, using a tablet-based and a mainframe system. The intra-assessor reliability and standard error of measurement for the cross-sectional area and/or thickness were assessed by analysis of variance. The error variance was statistically compared across age groups and machines. Results Eighteen physically active older adults (mean age 73.8 (SD: 4.9) years) and ten younger adults (mean age 21.9 (SD: 1.8) years) participated in the study. In older adults, the standard error of measurement ranged from 2.8 to 11.9%. The ICC ranged from 0.57 to 0.97, but was excellent in most cases. The error variance for six morphology measures was statistically smaller in younger adults, but was small in older adults as well. When different error variances were observed across machines, overall, the tablet-based device showed superior repeatability. Conclusions This intra-assessor reliability study showed that a tablet-based ultrasound machine can be reliably used to assess the morphology of selected foot muscles in older adults, with the exception of plantar fascia thickness. Although the measurement errors were sometimes smaller in younger adults, they seem adequate in older adults to detect group mean hypertrophy as a response to training. A tablet-based ultrasound device seems to be a reliable alternative to a mainframe system. This advocates its use when foot muscle morphology in older adults is of interest.
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Market competition and global financial uncertainty have been the principal drivers that impel aviation companies to proceed to budget cuts, including decreases in salary and work force levels, in order to ensure viability and sustainability. Under the concepts of Maslow and Herzberg’s motivation theories, the current paper unfolds the influence of employment cost fluctuations on an aviation organization’s accidents attributed to human error. This study exploited financial and accident data over a period of 13 years, and explored if rates of accidents attributed to human errors of flight, maintenance and ramp crews, correlate with the average employment expenditures (N=13). In addition, the study took into account the relationship between average task load (ratio of flying hours per employee) and accident rates related to human error since task load, as part of total workload, is a constraint of modern complex systems. The results revealed strong correlations amongst accident rates linked to human error with the average employment costs and task load. The use of more specific data per aviation organizational department and professional group may further validate the results of this study. Organizations that seek to explore the 2 association between human error and employment budget and task load might appropriately adapt the approach proposed.
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This paper aims to describe how we change our mind. As any human knows from his or her own experience, this does not always come naturally to us. This dissertation therefore aims to find fault in Seneca’s assertion: not only to err is human, but it is also human to persist in this mistake despite evidence to the contrary.In this paper I will argue that changing one’s mind is regulated through emotions, building on Damasio’s thoughts that emotions are not a luxury, but essential to rational thinking and normal behavior. His landmark book “Descarte’s Error“ (Damasio and Sutherland 1996) inspired the title of the current work. This research has been triggered by my experience in industry, where I have been lucky enough to have collaborated with many talented, friendly and rather stubborn people for over 20 years.Referentiede Boer, R.J. (2011), Seneca's Error: The Intervening Effect of Emotions on Mental Model Preservation , Symposium on Human Factors for Future Aviation, Schiphol Oost, The Netherlands
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The assumptions of the model for factor analysis do not exclude a class of indeterminate covariances between factors and error variables (Grayson, 2003). The construction of all factors of the model for factor analysis is generalized to incorporate indeterminate factor-error covariances. A necessary and sufficient condition is given for indeterminate factor-error covariances to be arbitrarily small, for mean square convergence of the regression predictor of factor scores, and for the existence of a unique determinate factor and error variable. The determinate factor and error variable are uncorrelated and satisfy the defining assumptions of factor analysis. Several examples are given to illustrate the results.
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Hoe repareer je en maak je op een structurele manier IT-systemen verantwoord, voor de nieuwe toepassingen? Nanda Piersma doet een oproep om dit vraagstuk ook neer te leggen bij de ontwerpers en bouwers van digitale systemen. Hoe kunnen zij IT-systemen bouwen die verantwoord zijn en van waarde in de maatschappij? Zonder wetten te overtreden of de economische waarde van de (IT-) producten te verminderen? De wens om verantwoord te gaan werken, betekent een volwassenheidsproces voor de IT-sector. Ook de gebruikers van de systemen zullen een bewustwording moeten ondergaan en verantwoordelijker gebruik gaan maken van de systemen. In haar boek betoogt Nanda Piersma wat ‘verantwoord’ betekent in een IT-context en hoe de (door)ontwikkeling van IT-systemen zodanig kan worden uitgevoerd zodat het ons vertrouwen ook verdient.
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Abstract In this paper several meaningful audio icons of classic arcade games such as Pong, Donkey Kong, Mario World and Pac-Man are analyzed, using the PRAAT software for speech analysis and musical theory. The analysis results are used to describe how these examples of best practice sound design obtain their meaning in the player's perception. Some aspects can be related to the use of tonal hierarchy (e.g. Donkey Kong and Mario World) which is a western culture related aspect of musical meaning. Other aspects are related to universal expressions of meaning such as the theory of misattribution, prosody, vocalization and cross-modal perceptions such as brightness and the uncanny valley hypothesis. Recent studies in the field of cognitive neuroscience support the universal and meaningful potential of all these aspects. The relationship between language related prosody, vocalization and phonology, and music seems to be an especially successful design principle for universally meaningful music icons in game sound design.
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The COMPASS system (IBADosimetry) is a quality assurance (QA) tool whichreconstructs 3D doses inside a phantom or a patient CT. The dose is predictedaccording to the RT plan with a correction derived from 2D measurementsof a matrix detector. This correction method is necessary since a directreconstruction of the fluence with a high resolution is not possible becauseof the limited resolution of the matrix used, but it comes with a blurring of thedosewhich creates inaccuracies in the dose reconstruction. This paper describesthe method and verifies its capability to detect errors in the positioning of aMLC with 10 mm leaf width in a phantom geometry. Dose reconstruction wasperformed forMLC position errors of various sizes at various locations for bothrectangular and intensity-modulated radiotherapy (IMRT) fields and comparedto a reference dose. It was found that the accuracy with which an error inMLCposition is detected depends on the location of the error relative to the detectorsin the matrix. The reconstructed dose in an individual rectangular field for leafpositioning errors up to 5 mm was correct within 5% in 50% of the locations.At the remaining locations, the reconstruction of leaf position errors larger than3 mm can show inaccuracies, even though these errors were detectable in thedose reconstruction. Errors larger than 9 mm created inaccuracies up to 17% ina small area close to the penumbra. The QA capability of the system was testedthrough gamma evaluation. Our results indicate that themean gamma providedby the system is slightly increased and that the number of points above gamma 1ensures error detection for QA purposes. Overall, the correction kernel methodused by the COMPASS system is adequate to perform QA of IMRT treatmentplans with a regular MLC, despite local inaccuracies in the dose reconstruction.
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A rail-guided robotic system is currently being designed for the inspection of ballast water tanks in ships. This robotic system will manipulate sensors toward the interior walls of the tank. In this paper, the influence of rail compliance on the end-effector position error due to ship movement is investigated. An analytical model of the six degrees-of-freedom (DOF) rail stiffness is presented and implemented in a reduced-order analytical frequency response model. This model describes the transfer function between ship acceleration and end-effector position as a function of rail geometry and material properties. Moreover, the influence of the robot compliance is investigated, resulting in design parameters for the robot. The models and calculations are evaluated and compared with a multibody model and prove to be accurate. The analytic models indicate whether or not a proposed robotic system is feasible and if so, optimize rail dimensions, material and robot design. A use-case scenario has been developed which shows that the proposed design will be unlikely to meet the requirements of this robot system design; therefore an alternative design strategy is recommended.
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We assessed how golfers cope with the commonly observed systematic overshoot errors in the perception of the direction between the ball and the hole. Experiments 1 and 2, in which participants were required to rotate a pointer such that it pointed to the center of the hole, showed that errors in perceived direction (in degrees of deviation from the perfect aiming line) are destroyed when the head is constrained to move within a plane perpendicular to the green. Experiment 3 compared the errors in perceived direction and putting errors of novice and skilled players. Unlike the perceived direction, putting accuracy (in degrees of deviation from the perfect aiming line) was not affected by head position. Novices did show a rightward putting error, while skilled players did not. We argue that the skill-related differences in putting accuracy reflect a process of recalibration. Implications for aiming in golf are discussed.
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