55,841 research outputs found
Aircrew coordination and decisionmaking: Peer ratings of video tapes made during a full mission simulation
Six professionally active, retired captains rated the coordination and decisionmaking performances of sixteen aircrews while viewing videotapes of a simulated commercial air transport operation. The scenario featured a required diversion and a probable minimum fuel situation. Seven point Likert-type scales were used in rating variables on the basis of a model of crew coordination and decisionmaking. The variables were based on concepts of, for example, decision difficulty, efficiency, and outcome quality; and leader-subordin ate concepts such as person and task-oriented leader behavior, and competency motivation of subordinate crewmembers. Five-front-end variables of the model were in turn dependent variables for a hierarchical regression procedure. The variance in safety performance was explained 46%, by decision efficiency, command reversal, and decision quality. The variance of decision quality, an alternative substantive dependent variable to safety performance, was explained 60% by decision efficiency and the captain's quality of within-crew communications. The variance of decision efficiency, crew coordination, and command reversal were in turn explained 78%, 80%, and 60% by small numbers of preceding independent variables. A principle component, varimax factor analysis supported the model structure suggested by regression analyses
Crew Communication as a Factor in Aviation Accidents
The crew communication process is analyzed. Planning and explanation are shown to be well-structured discourse types, described by formal rules. These formal rules are integrated with those describing the other most important discourse type within the cockpit: the command-and-control speech act chain. The latter is described as a sequence of speech acts for making requests (including orders and suggestions), for making reports, for supporting or challenging statements, and for acknowledging previous speech acts. Mitigation level, a linguistic indication of indirectness and tentativeness in speech, was an important variable in several hypotheses, i.e., the speech of subordinates is more mitigated than the speech of superiors, the speech of all crewmembers is less mitigated when they know that they are in either a problem or emergency situation, and mitigation is a factor in failures of crewmembers to initiate discussion of new topics or have suggestions ratified by the captain. Test results also show that planning and explanation are more frequently performed by captains, are done more during crew- recognized problems, and are done less during crew-recognized emergencies. The test results also indicated that planning and explanation are more frequently performed by captains than by other crewmembers, are done more during crew-recognized problems, and are done less during-recognized emergencies
Strong Limit on a Variable Proton-to-Electron Mass Ratio from Molecules in the Distant Universe
The Standard Model of particle physics assumes that the so-called fundamental
constants are universal and unchanging. Absorption lines arising in molecular
clouds along quasar sightlines offer a precise test for variations in the
proton-to-electron mass ratio, mu, over cosmological time and distance scales.
The inversion transitions of ammonia are particularly sensitive to mu compared
to molecular rotational transitions. Comparing the available ammonia spectra
observed towards the quasar B0218+357 with new, high-quality rotational
spectra, we present the first detailed measurement of mu with this technique,
limiting relative deviations from the laboratory value to |dmu/mu| <
1.8x10^{-6} (95% confidence level) at approximately half the Universe's current
age - the strongest astrophysical constraint to date. Higher-quality ammonia
observations will reduce both the statistical and systematic uncertainties in
these measurements.Comment: Science, 20th June 2008. 22 pages, 5 figures (12 EPS files), 2
tables, including Supporting Online Material; v2: Corrected reference for
laboratory mu-variation bound
Paterno v. Laser Spine Institute: Did the New York Court of Appeals\u27 Misapplication of Unjustified Policy Fears Lead to A Miscarriage of Justice and the Creation of Inadequate Precedent for the Proper Use of the Empire State’s Long-Arm Statute?
This article discusses CPLR section 302(a)(1) as applied by the New York State Court of Appeals in Paterno v. Laser Spine Institute. The Paterno Court failed to properly apply a statutory jurisdictional analysis by conflating it with a due process inquiry. Also, the Court unnecessarily balanced the interests of the Empire State\u27s citizens in having a forum for access to justice with unjustified policy fears of potential costs to the state from assertions of in personam jurisdiction. Furthermore, the Court\u27s policy focus4 on the protection of medical doctors from lawsuits and the prevention of “floodgate” litigation which would adversely affect the medical profession was not justified by the record and created poor precedent for subsequent judicial application of the state\u27s long-arm statute.
This article will examine CPLR section 302(a)(1), under Paterno v. Laser Spine Institute and some of its predecessors, to demonstrate that sometimes overarching policy concerns get in the way of a strict statutory analysis under CPLR section 302(a)(1). We analyze how the Court of Appeals in Paterno conflated the jurisdictional basis and due process analyses and determine that the Court, based on a faulty statutory analysis, erroneously decided that there was no statutory jurisdiction.
Our article is divided into six parts. Part II briefly discusses the history of the CPLR and the manner of obtaining jurisdiction through Sections 301 and 302, focusing mainly on long-arm jurisdiction. Part III discusses and analyzes leading cases, which involve the application of CPLR 302 in obtaining personal jurisdiction. Part IV discusses a recent case, Paterno v. Laser Spine Institute, in great detail, and Part V engages in a critical analysis of Paterno with reference to a similar case, Grimaldi v. Guinn. Part VI addresses policy considerations and Part VII concludes with a discussion of how the Paterno Court entangled its jurisdictional analysis and where the Court may be headed with its future application of CPLR section 302(a)(1)
A human factors methodology for real-time support applications
A general approach to the human factors (HF) analysis of new or existing projects at NASA/Goddard is delineated. Because the methodology evolved from HF evaluations of the Mission Planning Terminal (MPT) and the Earth Radiation Budget Satellite Mission Operations Room (ERBS MOR), it is directed specifically to the HF analysis of real-time support applications. Major topics included for discussion are the process of establishing a working relationship between the Human Factors Group (HFG) and the project, orientation of HF analysts to the project, human factors analysis and review, and coordination with major cycles of system development. Sub-topics include specific areas for analysis and appropriate HF tools. Management support functions are outlined. References provide a guide to sources of further information
Teacher and student perceptions of the development of learner autonomy : a case study in the biological sciences
Biology teachers in a UK university expressed a majority view that student learning autonomy increases with progression through university. A minority suggested that pre-existing diversity in learning autonomy was more important and that individuals not cohorts differ in their learning autonomy. They suggested that personal experience prior to university and age were important and that mature students are more autonomous than 18-20 year olds. Our application of an autonomous learning scale (ALS) to four year-groups of biology students confirmed that the learning autonomy of students increases through their time at university but not that mature students are necessarily more autonomous than their younger peers. It was evident however that year of study explained relatively little
Photometric reverberation mapping of 3C120
We present the results of a five month monitoring campaign of the local
active galactic nuclei (AGN) 3C120. Observations with a median sampling of two
days were conducted with the robotic 15cm telescope VYSOS-6 located near Cerro
Armazones in Chile. Broad band (B,V) and narrow band (NB) filters were used in
order to measure fluxes of the AGN and the H_beta broad line region (BLR)
emission line. The NB flux is constituted by about 50% continuum and 50% H_beta
emission line. To disentangle line and continuum flux, a synthetic H_beta light
curve was created by subtracting a scaled V-band light curve from the NB light
curve. Here we show that the H_beta emission line responds to continuum
variations with a rest frame lag of 23.6 +/- 1.69 days. We estimate a virial
mass of the central black hole M_BH = 57 +/- 27 * 10^6 solar masses, by
combining the obtained lag with the velocity dispersion of a single
contemporaneous spectrum. Using the flux variation gradient (FVG) method, we
determined the host galaxy subtracted rest frame 5100A luminosity at the time
of our monitoring campaign with an uncertainty of 10% (L_AGN = 6.94 +/- 0.71*
10^43 ergs^-1). Compared with recent spectroscopic reverberation results, 3C120
shifts in the R_BLR - L_AGN diagram remarkably close to the theoretically
expected relation of R-L^0.5. Our results demonstrate the performance of
photometric AGN reverberation mapping, in particular for efficiently
determining the BLR size and the AGN luminosityComment: 11 pages, 11 figures, Published in Astronomy and Astrophysic
Particle-in-cell simulation of a mildly relativistic collision of an electron-ion plasma carrying a quasi-parallel magnetic field: Electron acceleration and magnetic field amplification at supernova shocks
Plasma processes close to SNR shocks result in the amplification of magnetic
fields and in the acceleration of electrons, injecting them into the diffusive
acceleration mechanism. The acceleration of electrons and the B field
amplification by the collision of two plasma clouds, each consisting of
electrons and ions, at a speed of 0.5c is investigated. A quasi-parallel
guiding magnetic field, a cloud density ratio of 10 and a plasma temperature of
25 keV are considered. A quasi-planar shock forms at the front of the dense
plasma cloud. It is mediated by a circularly left-hand polarized
electromagnetic wave with an electric field component along the guiding
magnetic field. Its propagation direction is close to that of the guiding field
and orthogonal to the collision boundary. It has a low frequency and a
wavelength that equals several times the ion inertial length, which would be
indicative of a dispersive Alfven wave close to the ion cyclotron resonance
frequency of the left-handed mode (ion whistler), provided that the frequency
is appropriate. However, it moves with the super-alfvenic plasma collision
speed, suggesting that it is an Alfven precursor or a nonlinear MHD wave such
as a Short Large-Amplitude Magnetic Structure (SLAMS). The growth of the
magnetic amplitude of this wave to values well in excess of those of the
quasi-parallel guiding field and of the filamentation modes results in a
quasi-perpendicular shock. We present evidence for the instability of this mode
to a four wave interaction. The waves developing upstream of the dense cloud
give rise to electron acceleration ahead of the collision boundary. Energy
equipartition between the ions and the electrons is established at the shock
and the electrons are accelerated to relativistic speeds.Comment: 16 pages, 18 figures, Accepted for publication by Astron & Astrophy
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