Tiffany S Lin

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Industrial logging has become the most extensive land use in Central Africa, with more than 600,000 square kilometers (30%) of forest currently under concession. With use of a time series of satellite imagery for the period from 1976 to 2003, we measured 51,916 kilometers of new logging roads. The density of roads across the forested region was 0.03(More)
The attenuation coefficient in two groups (n1 = 70; n2 = 59) of pathologically graded in vitro human liver specimens was measured over a frequency range from 1.25-8.0 MHz and fitted to a power law model. The slopes of the power law curves at 5 MHz were correlated with pathological scores for fat in Group I, which consisted of normal and fatty livers (no(More)
The speed of sound in normal and diffusely-diseased liver specimens was measured. There were four experimental groups, consisting of normal (n = 21), fatty (n = 7), fibrotic (n = 7) and mixed fatty and fibrotic (n = 9). These classifications were based on histological grading. We found that the results corroborate and extend most of the results of Bamber(More)
The attenuation coefficient in 38 pathologically graded in vitro liver specimens was measured over a frequency range from 1.25-8 MHz and fitted to the power law model. The attenuation in the normal group (n = 17) exhibited a frequency dependence of the form 0.399f1.139; in the mild disease group (n = 13), it exhibited a dependence of the form 0.395f1.212;(More)
A transmission method for speed-of-sound measurement in biological tissue specimens is described. The technique involves detecting the time of arrival of a transmitted pulse with a small hydrophone that penetrates the tissue sample in accurately known increments. The technique allows localized measurements to be made without the error-prone task of(More)
The effects of prefiltering and the choice of time-delay estimators and statistical data reduction techniques on the precision of speed-of-sound estimation were investigated using the beam-tracking technique. It was found that prefiltering the data with an ideal 50-kHz low-pass filter improved the precision of the estimation in all cases. Echo(More)
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