756 research outputs found
Launch Commit Criteria Monitoring Agent
The Spaceport Processing Systems Branch at NASA Kennedy Space Center has developed and deployed a software agent to monitor the Space Shuttle's ground processing telemetry stream. The application, the Launch Commit Criteria Monitoring Agent, increases situational awareness for system and hardware engineers during Shuttle launch countdown. The agent provides autonomous monitoring of the telemetry stream, automatically alerts system engineers when predefined criteria have been met, identifies limit warnings and violations of launch commit criteria, aids Shuttle engineers through troubleshooting procedures, and provides additional insight to verify appropriate troubleshooting of problems by contractors. The agent has successfully detected launch commit criteria warnings and violations on a simulated playback data stream. Efficiency and safety are improved through increased automation
Statistical study of conductance properties in one-dimensional quantum wires focusing on the 0.7 anomaly
The properties of conductance in one-dimensional (1D) quantum wires are
statistically investigated using an array of 256 lithographically-identical
split gates, fabricated on a GaAs/AlGaAs heterostructure. All the split gates
are measured during a single cooldown under the same conditions. Electron
many-body effects give rise to an anomalous feature in the conductance of a
one-dimensional quantum wire, known as the `0.7 structure' (or `0.7 anomaly').
To handle the large data set, a method of automatically estimating the
conductance value of the 0.7 structure is developed. Large differences are
observed in the strength and value of the 0.7 structure [from to
], despite the constant temperature and identical device
design. Variations in the 1D potential profile are quantified by estimating the
curvature of the barrier in the direction of electron transport, following a
saddle-point model. The 0.7 structure appears to be highly sensitive to the
specific confining potential within individual devices.This is the author's accepted manuscript. The final version is published by ACS in Physical Review B and can be found here: http://journals.aps.org/prb/abstract/10.1103/PhysRevB.90.045426
Assisted extraction of the energy level spacings and lever arms in direct current bias measurements of one-dimensional quantum wires, using an image recognition routine
A multiplexer technique is used to individually measure an array of 256 split gates on a single
GaAs/AlGaAs heterostructure. This results in the generation of large volumes of data, which
requires the development of automated data analysis routines. An algorithm is developed to find
the spacing between discrete energy levels, which form due to transverse confinement from the split
gate. The lever arm, which relates split gate voltage to energy, is also found from the measured
data. This reduces the time spent on the analysis. Comparison with estimates obtained visually
show that the algorithm returns reliable results for subband spacing of split gates measured at
1:4 K. The routine is also used to assess DC bias spectroscopy measurements at lower temperatures
(50 mK). This technique is versatile and can be extended to other types of measurements. For
example, it is used to extract the magnetic field at which Zeeman-split 1D subbands cross one
another.This work was supported by the Engineering and Physical Sciences Research Council grant No. EP/IO14268/1.This is the accepted manuscript. The final version is available from AIP at http://scitation.aip.org/content/aip/journal/jap/117/1/10.1063/1.4905484
Implementation of virtual OSCE in Health Professions Education: a Systematic Review
Introduction: The Objective Structured Clinical Examination (OSCE) has been widely
used in health professions education since the 1970s. The global disruption caused
by the COVID-19 pandemic restricted in-person assessments and medical educators
globally sought alternative means to assess and certify students and trainees to meet
the acute demand for health-care workers. One such solution was through virtual
OSCE (vOSCE), which modified traditional in-person OSCE using videoconference
platforms. This meta-ethnography sought to synthesise qualitative literature on candidates' and assessors' experiences of vOSCE to evaluate whether it may have a role
in future assessment practices.
Methods: In June 2022, we systematically searched PsycINFO, Medline and ERIC for
peer-reviewed qualitative and mixed-methods articles that described candidates' and
assessors' experiences of virtual OSCE in health professions education. Of 1069 articles identified, 17 were synthesised using meta-ethnography.
Results: The final synthesis represented 1190 candidates and assessors from faculties of medicine, dentistry, nursing, pharmacy and osteopathy. We developed our
findings into four key concepts. ‘Strengthening confidence in a virtual environment’
highlighted attempts to overcome and mitigate concerns associated with transitioning from in-person to virtual assessment. ‘Understanding the scope of use as an
assessment’ reflected on the suitability of vOSCE in assessing various skills. ‘Refining
operational processes’ emphasised the technical challenges of implementing vOSCE
and impacts on accessibility and resources. ‘Envisioning its future role’ considered
the applicability of vOSCE in the climate of rapid development in telehealth.
Conclusion: This meta-ethnography highlighted that although vOSCE was primarily
considered a temporary and crisis response, candidates and assessors recognised
positive, as well as negative, consequences of the transition towards them. Moving
forward, medical education policymakers should carefully consider the extent to
which elements of vOSCE could be incorporated into assessment systems, particularly in light of the rise of telehealth in clinical practice
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