1,722,262 research outputs found
Simpson David Huffaker c. mid 1880s
Simpson David Huffaker was the father of Frances who married Wesley Walton in 1857 in South Cottonwood (as it was then called). Simpson was born in 1812 and died in 1891
The spiritual forces involved in the present war : two addresses /
Rev. and abridged. "This pamphlet takes the place of an address entitled: 'Should a Christian fight?' which the Censor would not permit to be published" -- Cover; Also available online at: http://nla.gov.au/nla.aus-vn428317; FERG copy from Ferguson First World War, 1914-1919 pamphlet collection
Maximum entropy image processing in two and three dimensional single photon nuclear medicine imaging
Maximum entropy is applied to the problem of reconstructing nuclear medicine images. The physics of the formation of these images is reviewed showing a number of phenomena which degrade both two and three dimensional estimates of tracer distribution. The development and theoretical justification of maximum entropy as an image processing technique is also discussed. Maximum entropy is then applied to the problem of image reconstruction in a series of approximations.Firstly, a single planar nuclear medicine image is modelled as a convolution of a two dimensional distribution with a point-spread-function. Maximum entropy deconvolution is described and applied to the problem of restoring the blur free distribution. This technique improves image quality assessed by a number of criteria.A second, more accurate model of the planar imaging process is developed: blurring effects are modelled to depend on the source to camera distance. The planar image is considered a weighted sum of a series of convolutions with different point spread functions. Simultaneously acquired opposed views are considered and from these, a three dimensional distribution reconstructed. A weighted projection of this distribution appears a better planar representation of the distribution than solutions found by the previous method.Finally, the full three dimensional distribution is reconstructed from a series of views. The effects of attenuation collimator response and scatter on the projections are approximately modelled. The attenuation coefficient is considered to be constant inside the surface of the object to be reconstructed. Blurring effects due to collimator and scatter are considered to depend only on the distance between source and camera.</p
A new lectotype for Isolepis levynsiana (Cyperaceae)
Muasya, A. Muthama, Simpson, David A. (2021): A new lectotype for Isolepis levynsiana (Cyperaceae). Phytotaxa 524 (1): 65-66, DOI: 10.11646/phytotaxa.524.1.
Justicia prachuapensis, a new name for J. hansenii Rueangs. & Chantar. (Acanthaceae), a later homonym
Rueangsawang, Kanokorn, Chantaranothai, Pranom, Simpson, David A. (2014): Justicia prachuapensis, a new name for J. hansenii Rueangs. & Chantar. (Acanthaceae), a later homonym. Phytotaxa 162 (2): 120-120, DOI: 10.11646/phytotaxa.162.2.8, URL: http://dx.doi.org/10.11646/phytotaxa.162.2.
Taxonomic notes on the genus Justicia (Acanthaceae) from Thailand
Rueangsawang, Kanokorn, Chantaranothai, Pranom, Simpson, David A. (2013): Taxonomic notes on the genus Justicia (Acanthaceae) from Thailand. Phytotaxa 130 (1): 43-49, DOI: 10.11646/phytotaxa.130.1.5, URL: https://www.mendeley.com/catalogue/2c1ae16e-8388-368a-96d0-64c533cc44e0
FIGURE 2 in Taxonomic notes on the genus Justicia (Acanthaceae) from Thailand
FIGURE 2. Distribution of J. hansenii in south-eastern Thailand. Closed circle (·) indicates collection locality.Published as part of Rueangsawang, Kanokorn, Chantaranothai, Pranom & Simpson, David A., 2013, Taxonomic notes on the genus Justicia (Acanthaceae) from Thailand, pp. 43-49 in Phytotaxa 130 (1) on page 45, DOI: 10.11646/phytotaxa.130.1.5, http://zenodo.org/record/508578
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