67,719 research outputs found
Husserlian Aspects of Wittgenstein"s Middle Period
It is not immediately obvious that there was anything\ud
connecting Husserl or phenomenology with Wittgenstein"s\ud
work, but with an examination of the evidence, this attitude\ud
can be changed. I will establish the modest probability that\ud
Wittgenstein had contact with the ideas of Husserl, and\ud
that the ideas of Husserl were either directly or indirectly\ud
influential in Wittgenstein"s work. Wittgenstein"s concern\ud
with phenomenology is most explicitly expressed in his\ud
Philosophical Remarks (hereafter Remarks), however\ud
there is tacit concern throughout most of his writing
Application of communications satellites to educational development
A summary of research is presented. The broad objectives of this interdisciplinary research effort were: (1) to assess the role of satellite communications as a means of improving education in the United States, as well as in less-developed areas of the world; (2) to generate basic knowledge which will aid in making rational decisions about satellite application in the field of education in the years ahead; (3) to devise systems and strategies for improving education; and (4) to educate individuals who will be knowledgeable about aspects of satellite communications policy which transcend any single discipline
Resistojet research and development, phase ii second quarterly progress report, 1 oct. - 31 dec. 1964
Transient propulsion performance of 10 watt fast heating resistojet engin
Time-resolved fuel injector flow characterisation based on 3D laser Doppler vibrometry
In order to enable investigations of the fuel flow inside unmodified
injectors, we have developed a new experimental approach to measure
time-resolved vibration spectra of diesel nozzles using a three dimensional
laser vibrometer. The technique we propose is based on the triangulation of the
vibrometer and fuel pressure transducer signals, and enables the quantitative
characterisation of quasi-cyclic internal flows without requiring modifications
to the injector, the working fluid, or limiting the fuel injection pressure.
The vibrometer, which uses the Doppler effect to measure the velocity of a
vibrating object, was used to scan injector nozzle tips during the injection
event. The data were processed using a discrete Fourier transform to provide
time-resolved spectra for valve-closed-orifice, minisac and microsac nozzle
geometries, and injection pressures ranging from 60 to 160MPa, hence offering
unprecedented insight into cyclic cavitation and internal mechanical dynamic
processes. A peak was consistently found in the spectrograms between 6 and
7.5kHz for all nozzles and injection pressures. Further evidence of a similar
spectral peak was obtained from the fuel pressure transducer and a needle lift
sensor mounted into the injector body. Evidence of propagation of the nozzle
oscillations to the liquid sprays was obtained by recording high-speed videos
of the near-nozzle diesel jet, and computing the fast Fourier transform for a
number of pixel locations at the interface of the jets. This 6-7.5kHz frequency
peak is proposed to be the natural frequency for the injector's main internal
fuel line. Other spectral peaks were found between 35 and 45kHz for certain
nozzle geometries, suggesting that these particular frequencies may be linked
to nozzle dependent cavitation phenomena.Comment: 12 pages, 10 figure
L1TV computes the flat norm for boundaries
We show that the recently introduced L1TV functional can be used to
explicitly compute the flat norm for co-dimension one boundaries. While this
observation alone is very useful, other important implications for image
analysis and shape statistics include a method for denoising sets which are not
boundaries or which have higher co-dimension and the fact that using the flat
norm to compute distances not only gives a distance, but also an informative
decomposition of the distance. This decomposition is made to depend on scale
using the "flat norm with scale" which we define in direct analogy to the L1TV
functional. We illustrate the results and implications with examples and
figures
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