1,495 research outputs found
Technical approaches for measurement of human errors
Human error is a significant contributing factor in a very high proportion of civil transport, general aviation, and rotorcraft accidents. The technical details of a variety of proven approaches for the measurement of human errors in the context of the national airspace system are presented. Unobtrusive measurements suitable for cockpit operations and procedures in part of full mission simulation are emphasized. Procedure, system performance, and human operator centered measurements are discussed as they apply to the manual control, communication, supervisory, and monitoring tasks which are relevant to aviation operations
The analysis of delays in simulator digital computing systems. Volume 1: Formulation of an analysis approach using a central example simulator model
The effects of spurious delays in real time digital computing systems are examined. Various sources of spurious delays are defined and analyzed using an extant simulator system as an example. A specific analysis procedure is set forth and four cases are viewed in terms of their time and frequency domain characteristics. Numerical solutions are obtained for three single rate one- and two-computer examples, and the analysis problem is formulated for a two-rate, two-computer example
Effectiveness of group-based self-management education for individuals with Type 2 diabetes:A systematic review with meta-analyses and meta-regression
Aims:
Patient education for the management of Type 2 diabetes can be delivered in various forms, with the goal of promoting and supporting positive self-management behaviours. This systematic review aimed to determine the effectiveness of group-based interventions compared with individual interventions or usual care for improving clinical, lifestyle and psychosocial outcomes in people with Type 2 diabetes.
Methods:
Six electronic databases were searched. Group-based education programmes for adults with Type 2 diabetes that measured glycated haemoglobin (HbA1c) and followed participants for ≥ 6 months were included. The primary outcome was HbA1c, and secondary outcomes included fasting blood glucose, weight, body mass index, waist circumference, blood pressure, blood lipid profiles, diabetes knowledge and self-efficacy.
Results:
Fifty-three publications describing 47 studies were included (n = 8533 participants). Greater reductions in HbA1c occurred in group-based education compared with controls at 6–10 months [n = 30 studies; mean difference (MD) = 3 mmol/mol (0.3%); 95% confidence interval (CI): −0.48, −0.15; P = 0.0002], 12–14 months [n = 27 studies; MD = 4 mmol/mol (0.3%); 95% CI: −0.49, −0.17; P < 0.0001], 18 months [n = 3 studies; MD = 8 mmol/mol (0.7%); 95% CI: −1.26, −0.18; P = 0.009] and 36–48 months [n = 5 studies; MD = 10 mmol/mol (0.9%); 95% CI: −1.52, −0.34; P = 0.002], but not at 24 months. Outcomes also favoured group-based education for fasting blood glucose, body weight, waist circumference, triglyceride levels and diabetes knowledge, but not at all time points. Interventions facilitated by a single discipline, multidisciplinary teams or health professionals with peer supporters resulted in improved outcomes in HbA1c when compared with peer-led interventions.
Conclusions:
Group-based education interventions are more effective than usual care, waiting list control and individual education at improving clinical, lifestyle and psychosocial outcomes in people with Type 2 diabetes.No Full Tex
Joint Bayesian component separation and CMB power spectrum estimation
We describe and implement an exact, flexible, and computationally efficient
algorithm for joint component separation and CMB power spectrum estimation,
building on a Gibbs sampling framework. Two essential new features are 1)
conditional sampling of foreground spectral parameters, and 2) joint sampling
of all amplitude-type degrees of freedom (e.g., CMB, foreground pixel
amplitudes, and global template amplitudes) given spectral parameters. Given a
parametric model of the foreground signals, we estimate efficiently and
accurately the exact joint foreground-CMB posterior distribution, and therefore
all marginal distributions such as the CMB power spectrum or foreground
spectral index posteriors. The main limitation of the current implementation is
the requirement of identical beam responses at all frequencies, which restricts
the analysis to the lowest resolution of a given experiment. We outline a
future generalization to multi-resolution observations. To verify the method,
we analyse simple models and compare the results to analytical predictions. We
then analyze a realistic simulation with properties similar to the 3-yr WMAP
data, downgraded to a common resolution of 3 degree FWHM. The results from the
actual 3-yr WMAP temperature analysis are presented in a companion Letter.Comment: 23 pages, 16 figures; version accepted for publication in ApJ -- only
minor changes, all clarifications. More information about the WMAP3 analysis
available at http://www.astro.uio.no/~hke under the Research ta
Functional requirements for the man-vehicle systems research facility
The NASA Ames Research Center proposed a man-vehicle systems research facility to support flight simulation studies which are needed for identifying and correcting the sources of human error associated with current and future air carrier operations. The organization of research facility is reviewed and functional requirements and related priorities for the facility are recommended based on a review of potentially critical operational scenarios. Requirements are included for the experimenter's simulation control and data acquisition functions, as well as for the visual field, motion, sound, computation, crew station, and intercommunications subsystems. The related issues of functional fidelity and level of simulation are addressed, and specific criteria for quantitative assessment of various aspects of fidelity are offered. Recommendations for facility integration, checkout, and staffing are included
A re-analysis of the three-year WMAP temperature power spectrum and likelihood
We analyze the three-year WMAP temperature anisotropy data seeking to confirm
the power spectrum and likelihoods published by the WMAP team. We apply five
independent implementations of four algorithms to the power spectrum estimation
and two implementations to the parameter estimation. Our single most important
result is that we broadly confirm the WMAP power spectrum and analysis. Still,
we do find two small but potentially important discrepancies: On large angular
scales there is a small power excess in the WMAP spectrum (5-10% at l<~30)
primarily due to likelihood approximation issues between 13 <= l <~30. On small
angular scales there is a systematic difference between the V- and W-band
spectra (few percent at l>~300). Recently, the latter discrepancy was explained
by Huffenberger et al. (2006) in terms of over-subtraction of unresolved point
sources. As far as the low-l bias is concerned, most parameters are affected by
a few tenths of a sigma. The most important effect is seen in n_s. For the
combination of WMAP, Acbar and BOOMERanG, the significance of n_s =/ 1 drops
from ~2.7 sigma to ~2.3 sigma when correcting for this bias. We propose a few
simple improvements to the low-l WMAP likelihood code, and introduce two
important extensions to the Gibbs sampling method that allows for proper
sampling of the low signal-to-noise regime. Finally, we make the products from
the Gibbs sampling analysis publically available, thereby providing a fast and
simple route to the exact likelihood without the need of expensive matrix
inversions.Comment: 14 pages, 7 figures. Accepted for publication in ApJ. Numerical
results unchanged, but interpretation sharpened: Likelihood approximation
issues at l=13-30 far more important than potential foreground issues at l <=
12. Gibbs products (spectrum and sky samples, and "easy-to-use" likelihood
module) available from http://www.astro.uio.no/~hke/ under "Research
The Distribution of the Major Economies' Effort in the Durban Platform Scenarios
The feasibility of achieving climate stabilization consistent with the objective of 2 degrees C is heavily influenced by how the effort in terms of mitigation and economic resources will be distributed among the major economies. This paper provides a multi-model quantification of the mitigation commitment in ten major regions of the world for a diversity of allocation schemes. Our results indicate that a policy with uniform carbon pricing and no transfer payments would yield an uneven distribution of policy costs, which would be lower than the global average for OECD countries, higher for developing economies and the highest, for energy exporters. We show that a resource sharing scheme based on long-term convergence of per capita emissions would not resolve the issue of cost distribution. An effort sharing scheme which equalizes regional policy costs would yield an allocation of allowances comparable with the ones proposed by the Major Economies. Under such a scheme, emissions would peak between 2030 and 2045 for China and remain rather flat for India. In all cases, a very large international carbon market would be required
Tuneable Fabry–Perot etalon for terahertz radiation
Copyright © 2008 IOP Publishing Ltd and Deutsche Physikalische Gesellschaft. This is the published version of an article published in New Journal of Physics Vol. 10, article 033012. DOI:10.1088/1367-2630/10/3/033012An indium tin oxide-clad liquid crystal filled Fabry–Perot etalon structure has been shown to act as an effective narrow-band filter at terahertz frequencies. An applied voltage, which controls the alignment of the nematic liquid crystal allows the refractive index of the core to be tuned. Transmission spectra show well-defined resonant peaks which shift in position when the alignment is changed from planar to homeotropic. The measured transmission spectra agree well with the results of a multilayer optics model and the birefringence of the liquid crystals over this frequency range are determined as Δn = 0.15(± 0.01) and Δn = 0.08(± 0.01) for E7 and ZLI 2293, respectively
Chamber basis of the Orlik-Solomon algebra and Aomoto complex
We introduce a basis of the Orlik-Solomon algebra labeled by chambers, so
called chamber basis. We consider structure constants of the Orlik-Solomon
algebra with respect to the chamber basis and prove that these structure
constants recover D. Cohen's minimal complex from the Aomoto complex.Comment: 16 page
Attachment measures in middle childhood and adolescence: a systematic review of measurement properties
Background: Attachment theory proposes that humans develop representations of self and other in early childhood which are relatively stable across the life-course, and play a key role in psychological adaptation. However, to date, the psychometric properties of attachment measures in middle childhood and adolescence have not been evaluated in a systematic review. Method: A systematic review (PROSPERO ID: CRD42017057772) was conducted using COSMIN criteria. Two researchers independently searched MEDLINE, PsychINFO and Embase databases for relevant articles. Results: Fifty-four studies were included in the review. The methodological quality of studies was typically fair or poor, with only a smaller number of studies being rated as of good or excellent quality. The measurement properties of attachment measures in this age group were frequently rated as inadequate according to COSMIN criteria. The Child Attachment Interview (CAI) has the best psychometric properties of the interview and projective measures, and the Inventory of Parent and Peer Attachment (IPPA) the best evidence of the self-report measures. Overall, the evidence for the CAI and IPPA included both positive and negative findings relating to adequacy of measurement properties. Conclusions: Attachment measures in middle childhood and adolescence currently have limited evidence for the adequacy of their psychometric properties
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