Paraglider Reserve Parachute Deployment Under Radial Acceleration

2021 ◽  
Vol 92 (7) ◽  
pp. 579-587
Author(s):  
Matt Wilkes ◽  
Geoff Long ◽  
Rebecca Charles ◽  
Heather Massey ◽  
Clare Eglin ◽  
...  

INTRODUCTION: The paragliding reserve parachute system is safety-critical but underused, unstandardized, and known to fail. This study aimed to characterize reserve parachute deployment under radial acceleration to make recommendations for system design and paraglider pilot training.METHODS: There were 88 licensed amateur paraglider pilots who were filmed deploying their reserve parachutes from a centrifuge. Of those, 43 traveled forward at 4 G simulating a spiral dive, and 45 traveled backward at 3 G simulating a rotational maneuver known as SAT. Tests incorporated ecologically valid body, hand, and gaze positions, and cognitive loading and switching akin to real deployment. The footage was reviewed by subject matter experts and compared to previous work in linear acceleration.RESULTS: Of the pilots, 2.3 failed to extract the reserve container from the harness. SAT appeared more cognitively demanding than spiral, despite lower G. Participants located the reserve handle by touch not sight. The direction of travel influenced their initial contact with the harness: 82.9 searched first on their hip in spiral, 63.4 searched first on their thigh in SAT. Search patterns followed skeletal landmarks. Participants had little directional control over their throw.CONCLUSIONS: Paraglider pilots are part of the reserve system. Maladaptive behaviors observed under stress highlighted that components must work in harmony with pilots natural responses, with minimal cognitive demands or need for innovation or problem-solving. Recommendations include positioning prominent, tactile reserve handles overlying the pilots hip; deployment bags extractable with any angle of pull; deployment in a single sweeping backward action; and significantly increasing reserve deployment drills.Wilkes M, Long G, Charles R, Massey H, Eglin C, Tipton MJ. Paraglider reserve parachute deployment under radial acceleration. Aerosp Med Hum Perform. 2021; 92(7):579587.

2020 ◽  
Vol 51 (2) ◽  
pp. 479-493
Author(s):  
Jenny A. Roberts ◽  
Evelyn P. Altenberg ◽  
Madison Hunter

Purpose The results of automatic machine scoring of the Index of Productive Syntax from the Computerized Language ANalysis (CLAN) tools of the Child Language Data Exchange System of TalkBank (MacWhinney, 2000) were compared to manual scoring to determine the accuracy of the machine-scored method. Method Twenty transcripts of 10 children from archival data of the Weismer Corpus from the Child Language Data Exchange System at 30 and 42 months were examined. Measures of absolute point difference and point-to-point accuracy were compared, as well as points erroneously given and missed. Two new measures for evaluating automatic scoring of the Index of Productive Syntax were introduced: Machine Item Accuracy (MIA) and Cascade Failure Rate— these measures further analyze points erroneously given and missed. Differences in total scores, subscale scores, and individual structures were also reported. Results Mean absolute point difference between machine and hand scoring was 3.65, point-to-point agreement was 72.6%, and MIA was 74.9%. There were large differences in subscales, with Noun Phrase and Verb Phrase subscales generally providing greater accuracy and agreement than Question/Negation and Sentence Structures subscales. There were significantly more erroneous than missed items in machine scoring, attributed to problems of mistagging of elements, imprecise search patterns, and other errors. Cascade failure resulted in an average of 4.65 points lost per transcript. Conclusions The CLAN program showed relatively inaccurate outcomes in comparison to manual scoring on both traditional and new measures of accuracy. Recommendations for improvement of the program include accounting for second exemplar violations and applying cascaded credit, among other suggestions. It was proposed that research on machine-scored syntax routinely report accuracy measures detailing erroneous and missed scores, including MIA, so that researchers and clinicians are aware of the limitations of a machine-scoring program. Supplemental Material https://doi.org/10.23641/asha.11984364


Crisis ◽  
2010 ◽  
Vol 31 (5) ◽  
pp. 238-246 ◽  
Author(s):  
Paul W. C. Wong ◽  
Wincy S. C. Chan ◽  
Philip S. L. Beh ◽  
Fiona W. S. Yau ◽  
Paul S. F. Yip ◽  
...  

Background: Ethical issues have been raised about using the psychological autopsy approach in the study of suicide. The impact on informants of control cases who participated in case-control psychological autopsy studies has not been investigated. Aims: (1) To investigate whether informants of suicide cases recruited by two approaches (coroners’ court and public mortuaries) respond differently to the initial contact by the research team. (2) To explore the reactions, reasons for participation, and comments of both the informants of suicide and control cases to psychological autopsy interviews. (3) To investigate the impact of the interviews on informants of suicide cases about a month after the interviews. Methods: A self-report questionnaire was used for the informants of both suicide and control cases. Telephone follow-up interviews were conducted with the informants of suicide cases. Results: The majority of the informants of suicide cases, regardless of the initial route of contact, as well as the control cases were positive about being approached to take part in the study. A minority of informants of suicide and control cases found the experience of talking about their family member to be more upsetting than expected. The telephone follow-up interviews showed that none of the informants of suicide cases reported being distressed by the psychological autopsy interviews. Limitations: The acceptance rate for our original psychological autopsy study was modest. Conclusions: The findings of this study are useful for future participants and researchers in measuring the potential benefits and risks of participating in similar sensitive research. Psychological autopsy interviews may be utilized as an active engagement approach to reach out to the people bereaved by suicide, especially in places where the postvention work is underdeveloped.


2018 ◽  
Vol 39 (4) ◽  
pp. 196-203 ◽  
Author(s):  
Oulmann Zerhouni ◽  
Johan Lepage

Abstract. The present study is a first attempt to link self-reported difficulties in everyday emotion regulation (ER) with evaluative conditioning (EC). We conducted a within-subject study in which participants (n = 90) filled the Difficulties in Emotion Regulation Scale (DERS) and were exposed to neutral conditioned stimulus (CS) paired with mildly or highly arousing negative unconditioned stimuli (USs) and positive USs. Participants then filled a contingency awareness measure. Results showed (i) that CSs paired with highly arousing negative USs were more negatively evaluated, (ii) that the EC effect with highly and mildly arousing negative USs was stronger among participants with greater self-reported difficulties in everyday ER. Moreover, participants were more likely to be aware of the CS-US contingencies with highly (vs. mildly) arousing negative USs. Implications for the understanding of maladaptive behaviors and for future directions in EC research are discussed.


1959 ◽  
Author(s):  
David K. Trites ◽  
Albert L. Kubala ◽  
Bart B. Cobb
Keyword(s):  

1988 ◽  
Author(s):  
Frederick M. Siem ◽  
Thomas R. Carretta ◽  
Theresa A. Mercatante

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