111,719 research outputs found
Planning the digitisation, storage and access of large scale audiovisual archives
This paper presents ongoing work in PrestoSpace on how broadcast archives can plan large-scale, long-term digitization and storage projects. In our approach, carrier decay, technical obsolescence, and rapidly falling costs of mass storage are represented as a series of statistical and predictive models. The models include ongoing migration within a digital archive. The objective is to allow archive managers to investigate the trade-offs between how many items to transfer, the cost of transfer and storage, how long it will take, what quality can be achieved, how much will be lost, and what digital storage solutions to adopt over time. The process and models are based on digitization projects conducted by large broadcast archives that are currently migrating their collections into digital form. Whilst our focus is on broadcast archives, our findings should be readily transferable to other scenarios where there is a need to store large volumes of digital data over long periods of time
Status of advanced turboprop technology
Research is reviewed in the following areas: turboprop powered transport aircraft; wind tunnel aerodynamic and acoustics tests of model propellers; turboprop maintenance; and wind tunnel tests on airframe-turboprop interactions. Continued development of the technology for advanced turboprop transport was emphasized
Comparison of autokinetic movement perceived by normal persons and deaf subjects with bilateral labyrinthine defects
Comparison of autokinetic movement perceived by normal persons and deaf subjects with bilateral labyrinthine defects - Aerospace medicin
Altered susceptibility to motion sickness as a function of subgravity level
Large interindividual differences among 74 normal subjects in the change in susceptibility to motion sickness with effective lifting of the normal g-load by parabolic flight maneuvers were recorded with high test-retest reliability. Most subjects, who were required to make standardized head movements while seated in a chair rotating at a constant speed, demonstrated either a substantial increase or a decrease in susceptibility, in confirmation of a previous study, while a few appeared to be more or less unaffected by the 1 g to 0 g gravitational change. A similar test procedure conducted with eighteen of the subjects at lunar- and Martian-gravity levels revealed further interindividual differences in susceptiblity as a function of g-level. The subjects with gravity-dependent susceptibility revealed: (1) a progressive change in susceptibility as a function of g-load in either the positive or negative direction that was characteristic of the individual, (2) a susceptibility level that appeared to be maintained at the fractional g-load, and (3) immunity to motion sickness at all g-levels tested below the earth standard. The case history as well as ground-based functional and provocative tests of normal subjects proved to be inadequate in predicting susceptibility to motion sickness under subgravity conditions
Off-vertical rotation - A convenient precise means of exposing the passive human subject to a rotating linear acceleration vector
Disturbances of vestibular origin comprising motion sickness resulting from rotating tilted chai
Thermodynamics and kinetics of the sulfation of porous calcium silicate
The sulfation of plasma sprayed calcium silicate in flowing SO2/air mixtures at 900 and 1000 C was investigated thermogravimetrically. Reaction products were analyzed using electron microprobe and X-ray diffraction analysis techniques, and results were compared with thermodynamic predictions. The percentage, by volume, of SO2 in air was varied between 0.036 and 10 percent. At 10 percent SO2 the weight gain curve displays a concave downward shoulder early in the sulfation process. An analytical model was developed which treats the initial process as one which decays exponentially with increasing time and the subsequent process as one which decays exponentially with increasing weight gain. At lower SO2 levels the initial rate is controlled by the reactant flow rate. At 1100 C and 0.036 percent SO2 there is no reaction, in agreement with thermodynamic predictions
Motion sickness produced by head movement as a function of rotational velocity
Motion sickness produced by head movement as function of rotational velocit
Comparison of five levels of motion sickness severity as the basis for grading susceptibility
Less severe diagnosis for grading motion sickness susceptibilit
Magnitude of gravitoinertial force, an independent variable in egocentric visual localization of the horizontal
Magnitude of gravitoinertial force, independent variable in egocentric visual localization of horizontal-space perceptio
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