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2020-

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https://hdl.handle.net/10217/182111

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Browsing 2020- by Subject "3D scanning"

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    ItemOpen Access
    Analysis of 3D facial anthropometric measurements for respirator fit outcomes
    (Colorado State University. Libraries, 2023) Hobbs-Murphy, Kayna, author; Rosecrance, John, advisor; Brazile, Bill, committee member; Anderson, Brooke, committee member; Morris, Kristen, committee member; Hess, Ann, committee member
    Anthropometry is central to the development of efficacious products and environments (i.e., personal protective equipment, clothing, sunglasses, chairs, interior spaces, etc.) used by humans. Three-dimensional (3D) scanning is increasingly common for collecting anthropometric data, as it is faster and less intrusive than traditional manual methods. Additionally, 3D anthropometric methods used to derive facial dimensions provide greater contextual application in the development of respirators and facemasks. More than 2,000 3D facial scans were analyzed to assess measurement reliability and the dimensions of 27 facial features. This research represents the largest sample of 3D facial anthropometrics assessed to date. The three specific aims of the research included: 1) to assess the intra- and inter-rater reliability of 3D facial measurement methods, 2) to compare the 3D facial anthropometric summary statistics from the present study to relevant summary statistics from manual facial measurements found in the literature, and 3) to assess the presence of differences in 3D facial anthropometrics related to respirator fit, based on demographic factors of gender, race/ethnicity, and age. Post hoc analyses were completed to quantify 3D facial measurement differences between demographic groups (within the larger demographic categories of gender, race/ethnicity, and age group). The most notable results of this research include a) high reliability in 3D measurement data collection methods, b) differences in measurement data summary statistics between 3D and manual methods, and c) significant differences in facial measurements between demographic categories of gender (Male and Female/Other), race/ethnicity (White, Black, LatinX, Asian, and Other), and age (18-34, 35-54, and 55-72).
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    ItemOpen Access
    New insights into Pleistocene hominin butchery and tool choice from a 0.9 Ma fossil assemblage from the HEB site, Olduvai Gorge, Tanzania
    (Colorado State University. Libraries, 2021) Mwakyoma, Ipyana F., author; Pante, Michael C., advisor; Glantz, Michelle M., committee member; McKay, John, committee member
    Cut marks on animal bones have the potential to inform on hominin diet and tool use. Although these important traces of behavior appear as early as 3.4 Million years ago, they normally are rare in fossil assemblages in part due to the exceptional preservation of bone surfaces required to study them. Olduvai Gorge is unique in having many fossil assemblages with well-preserved cortical surfaces that allow identification and study of bone surface modifications. Most of these assemblages are from Beds I and II as fossil preservation is generally poor in the younger Beds. The present study analyzes the well-preserved fossil assemblage recovered from renewed excavations of the HEB site by the Olduvai Gorge Coring Project (OGCP). The HEB site is stratigraphically positioned in lower Bed IV, just above Tuff IVA, dating to ~0.9 Ma and was first excavated by Mary Leakey's team in 1962. These fossils exhibit a large number of cut marks and are in direct association with Acheulean tools; making this site important for inferring the feeding and tool use behavior of Homo erectus. Optical profilometry protocols developed by Pante et al (2017) were used to obtain 3D quantifiable micromorphological measurements of 256 experimentally created cutmarks, and 20 archaeological cutmarks from HEB site Olduvai Gorge. Focusing on the micromorphological measurements, this study used quadratic discriminant analyses models to classify the archaeological cutmarks from HEB site based on technology and raw materials types of the stone tools used to create those marks. The discriminant models on raw material types only, tool types only and both raw material and tool types had 64.8%, 77.3% and 68.4% classification accuracies respectively. Results from the models indicate that cut marks at HEB were made by using both flakes and biface tools, made from lava and quartzite raw materials. These results are consistent with Leakey (1994) excavations, which showed a significant prevalence of flakes and bifaces made from volcanic lava and quartzite raw materials. When interpreted in conjunction with butchery experiments, this study can help us understand hominin tool use and choices at HEB site, Olduvai Gorge - around 0.9 million years ago.