17,816 research outputs found
POPCORN: a Supervisory Control Simulation for Workload and Performance Research
A multi-task simulation of a semi-automatic supervisory control system was developed to provide an environment in which training, operator strategy development, failure detection and resolution, levels of automation, and operator workload can be investigated. The goal was to develop a well-defined, but realistically complex, task that would lend itself to model-based analysis. The name of the task (POPCORN) reflects the visual display that depicts different task elements milling around waiting to be released and pop out to be performed. The operator's task was to complete each of 100 task elements that ere represented by different symbols, by selecting a target task and entering the desired a command. The simulated automatic system then completed the selected function automatically. Highly significant differences in performance, strategy, and rated workload were found as a function of all experimental manipulations (except reward/penalty)
Voltage controlling mechanisms in low resistivity silicon solar cells: A unified approach
An experimental technique capable of resolving the dark saturation current into its base and emitter components is used as the basis of an analysis in which the voltage limiting mechanisms were determined for a variety of high voltage, low resistivity silicon solar cells. The cells studied include the University of Florida hi-low emitter cell, the NASA and the COMSAT multi-step diffused cells, the Spire Corporation ion-implanted emitter cell, and the University of New South Wales MINMIS and MINP cells. The results proved to be, in general, at variance with prior expectations. Most surprising was the finding that the MINP and the MINMIS voltage improvements are due, to a considerable extent, to a previously unrecognized optimization of the base component of the saturation current. This result is substantiated by an independent analysis of the material used to fabricate these devices
Influence of face lighting on the reliability of biometric facial readers
ArticleAt present, there is an increasing need to protect workplace entry and specially guarded
premises. In addition to standard access systems on a chip cards
are getting to the fore of biometric
identification systems such as readers for fingerprint, biometric scans faces and others. Biometric
readers face still improve, but still have a lot of blind spots, thanks to which their reliability and
user
-
friendline
ss decreases. One such problem is the light intensity in the room where the reading
device is located. The varying intensity of the light in the room causes a different illumination of
the person's face. It emphasizes or suppresses the main points of the f
ace that needed for user
authorization, and the whole identification process is prolonged and difficult. The reliability value
is significantly different from the value given by the manufacturers. It is very important to
highlight on this problem and begin
to address it by altering the current production engineering
Shortest Path Computation with No Information Leakage
Shortest path computation is one of the most common queries in location-based
services (LBSs). Although particularly useful, such queries raise serious
privacy concerns. Exposing to a (potentially untrusted) LBS the client's
position and her destination may reveal personal information, such as social
habits, health condition, shopping preferences, lifestyle choices, etc. The
only existing method for privacy-preserving shortest path computation follows
the obfuscation paradigm; it prevents the LBS from inferring the source and
destination of the query with a probability higher than a threshold. This
implies, however, that the LBS still deduces some information (albeit not
exact) about the client's location and her destination. In this paper we aim at
strong privacy, where the adversary learns nothing about the shortest path
query. We achieve this via established private information retrieval
techniques, which we treat as black-box building blocks. Experiments on real,
large-scale road networks assess the practicality of our schemes.Comment: VLDB201
Electronic Raman scattering in Magnetite, Spin vs. Charge gap
We report Raman scattering data of single crystals of magnetite (Fe3O4) with
Verwey transition temperatures (Tv) of 123 and 117K, respectively. Both single
crystals reveal broad electronic background extending up to 900 wavenumbers
(~110 meV). Redistribution of this background is observed when samples are
cooled below Tv. In particular, spectra of the low temperature phase show
diminished background below 300 wavenumbers followed by an enhancement of the
electronic background between 300 and 400 wavenumbers. To enhance the effect of
this background redistribution we divide the spectra just below the transition
by the spectra just above the transition. A resultant broad peak-like feature
is observed, centered at 370 wavenumbers (45 meV). The peak position of this
feature does not scale with the transition temperature. We discuss two
alternative assignments of this feature to a spin or charge gap in magnetite.Comment: 4 figures, 1 tabl
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