7,118 research outputs found
Summary of investigations of light scattering in highly reflecting pigmented coatings
Light scattering in highly reflecting pigmented coatings - silver bromide and particle suspensions and paint film
Investigation of light scattering in highly reflecting pigmented coatings. Volume 3 - Monte Carlo and other statistical investigations Final report, 1 May 1963 - 30 Sep. 1966
Monte Carlo methods, Mie theory, and random walk and screen models for predicting reflective properties of paint film
Correlation between acoustic scatterers and temperature gradient
A correlation has been found between acoustic scattering intensity at 87.5 kHz and smallscale vertical temperature gradients. Prior to the rise of the Sound Scattering Layer (SSL), there was a positive correlation, which persisted for about an hour after the upward evening SSL migration. After this time a diffuse downward migration was observed until the correlation was significantly negative. Possible rationales for this behavior are suggested
Gait Velocity Estimation using time interleaved between Consecutive Passive IR Sensor Activations
Gait velocity has been consistently shown to be an important indicator and
predictor of health status, especially in older adults. It is often assessed
clinically, but the assessments occur infrequently and do not allow optimal
detection of key health changes when they occur. In this paper, we show that
the time gap between activations of a pair of Passive Infrared (PIR) motion
sensors installed in the consecutively visited room pair carry rich latent
information about a person's gait velocity. We name this time gap transition
time and show that despite a six second refractory period of the PIR sensors,
transition time can be used to obtain an accurate representation of gait
velocity.
Using a Support Vector Regression (SVR) approach to model the relationship
between transition time and gait velocity, we show that gait velocity can be
estimated with an average error less than 2.5 cm/sec. This is demonstrated with
data collected over a 5 year period from 74 older adults monitored in their own
homes.
This method is simple and cost effective and has advantages over competing
approaches such as: obtaining 20 to 100x more gait velocity measurements per
day and offering the fusion of location-specific information with time stamped
gait estimates. These advantages allow stable estimates of gait parameters
(maximum or average speed, variability) at shorter time scales than current
approaches. This also provides a pervasive in-home method for context-aware
gait velocity sensing that allows for monitoring of gait trajectories in space
and time
Magnetic anisotropy of asbestos fibres
Original article can be found at : http://jap.aip.org/jap/ Copyright American Institute of PhysicsThe anisotropy of magnetic susceptibility of single asbestos fibers is measured. The alignment of both chrysotile and crocidolite fibers in magnetic fields is found to be due to the anisotropy. The average measured anisotropy of volume susceptibility is 0.40×10−6 for chrysotile and 83×10−6 for crocidolite. Fiber shape effects are estimated to contribute, on average, about 10% and 6%, respectively, to the total anisotropy of the two types of fiber. There is no evidence of significant permanent magnetic moments. The magnitude of the observed alignment makes the effect potentially useful in real-time detection of airborne asbestos fibers. The experimental technique developed in the study can be used for measuring the anisotropy of small particles of well-defined shape. High sensitivity of the technique permits the measurement of torques lower than 10−21 Nm on particles down to picogram mass.Peer reviewe
Investigation of Light Scattering in Highly Reflecting Pigmented Coatings Quarterly Report, Feb. 1 - May 1, 1966
Monte Carlo method applied to pigment particle clusters, and relevance of Mie scattering function to reflected ligh
Investigation of light scattering in highly reflecting pigmented coatings Quarterly report, Nov. 1, 1965 - Feb. 1, 1966
Monte Carlo treatment to find light scattering parameters of metal filled, reflecting pigmented coating
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