71,447 research outputs found
Human disorientation in a rotating spacecraft
The problem of disorientation in a rotating spacecraft is treated as an example of the general case of habituation to an unusual motion environment using all sensors and active movements. The dynamic response of the sensors is stressed. Several avenues for work on combating disorientation are mentioned
Aspects of SU(3) baryon extrapolation
We report on a recent chiral extrapolation, based on an SU(3) framework, of
octet baryon masses calculated in 2+1-flavour lattice QCD. Here we further
clarify the form of the extrapolation, the estimation of the infinite-volume
limit, the extracted low-energy constants and the corrections in the
strange-quark mass.Comment: 4 pages, 3 figures, pdftex, prepared for the proceedings of CIPANP
09, San Diego, USA, March 26-31, 200
Biophysical evaluation of the human vestibular system Semiannual status report, 1 Jul. - 31 Dec. 1966
Physical properties of labyrinth fluids in human vestibular syste
Biophysical evaluation of the human vestibular system Status report, Jul. 1969 - Sep. 1970
Biophysical evaluation of human vestibular system for aerospace application
Manual control of yaw motion with combined visual and vestibular cues
Measurements are made of manual control performance in the closed-loop task of nulling perceived self-rotation velocity about an earth-vertical axis. Self-velocity estimation was modelled as a function of the simultaneous presentation of vestibular and peripheral visual field motion cues. Based on measured low-frequency operator behavior in three visual field environments, a parallel channel linear model is proposed which has separate visual and vestibular pathways summing in a complementary manner. A correction to the frequency responses is provided by a separate measurement of manual control performance in an analogous visual pursuit nulling task. The resulting dual-input describing function for motion perception dependence on combined cue presentation supports the complementary model, in which vestibular cues dominate sensation at frequencies above 0.05 Hz. The describing function model is extended by the proposal of a non-linear cue conflict model, in which cue weighting depends on the level of agreement between visual and vestibular cues
CDTI: Crew Function Assessment
Man machine interaction often requires the operator to perform a sterotyped scan of instruments to monitor and/or control a system. Situations in which this type of behavior exists, such as instrument flight, scan pattern has been shown to be altered by imposition of simultaneous verbal tasks. The relationship between pilot visual scan of instruments and mental workload was described. A verbal loading task of varying difficulty caused pilots to stare at the primary instrument as the difficulty increased and to shed looks at instruments of less importance. The verbal loading task affected rank ordering of scanning sequences. The behavior of pilots with widely varying skill levels suggested that these effects occur most strongly at lower skill levels and are less apparent at high skill levels. Graphical interpretation of the hypothetical relationship between skill, workload, and performance is introduced and modeling results are presented to support this interpretation
Exploring the Revenue Mix of Nonprofit Organizations -- Does it Relate to Publicness
Nonprofit organizations offer a wide range of goods and services and seek funding from a variety of revenue sources. Our working theory n this paper is that the sources of funding are related to the services a nonprofit provides - specifically whether services are public, private, or mixed in the nature of their benefits. Using multiple subfields from three major fields in the National Taxonomy of Exempt Entities (NTEE), this study divides nonprofits according to service type, and estimates the impact of service character on particular revenue streams and overall level of revenue diversification. Generally, the proportion of revenues generated by program fees is lowest for the category deemed public, highest for those with mostly private benefits, and midway for "mixed" services which are private in character but entail substantial public benefits. Similarly, the more public a nonprofit's services, the greater the proportion of revenues it generates through donations. However, we also identify some puzzling results that suggest the need for continued investigation of the determinants of the sources and mixes of nonprofit income. Working Paper 07-3
Visual and control aspects of saccadic eye movements
Physiological, behavioral, and control investigation of rapid saccadic jump eye movement in human
Physiology of the visual control system
Neurophysiological aspects of eye movement in visual control system with differentiation of version and vergenc
Non-invasive, multichromatic eye oximeter Final report
Optical eye oximeter for measuring oxygen of choroidal blood for monitoring brain oxygen suppl
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