Molly Boeka Cannon

Comparison of fuzzy clustering methods and their applications to geophysics data

Fuzzy clustering algorithms are helpful when there exists a dataset with subgroupings of points having indistinct boundaries and overlap between the clusters. Traditional methods have been extensively studied and used on real-world data, but require users to have some knowledge of the outcome a priori in order to determine how many clusters to look for. Additionally, iterative algorithms choose the optimal number of clusters based on one of several performance measures. In this study, the authors compare the performance of three algorithms (fuzzy c-means, Gustafson-Kessel, and an iterative version of Gustafson-Kessel) when clustering a traditional data set as well as real-world geophysics data that were collected from an archaeological site in Wyoming. Areas of interest in the were identified using a crisp cutoff value as well as a fuzzy α-cut to determine which provided better elimination of noise and non-relevant points. Results indicate that the α-cut method eliminates more noise than the crisp cutoff values and that the iterative version of the fuzzy clustering algorithm is able to select an optimum number of subclusters within a point set (in both the traditional and real-world data), leading to proper indication of regions of interest for further expert analysis

Archaeological Fingerprinting and Fremont Figurines

Abstract After the anonymous 2011 return of a long-missing Pilling Fremont figurine, a multi-disciplinary research team conducted “fingerprint” analyses in an effort to match it to 10 mates with intact provenance. The Pilling figurines, crafted 1,000 years ago and cached in a remote sandstone niche in eastern Utah, are the most significant find of Fremont portable art ever documented because they occurred in situ and are unparalleled in detail and completeness. Most of the other 400-plus known Fremont figurines derive from secondary contexts, limiting inferences archaeologists might otherwise draw in domains ranging from Fremont exchange to inter- and intra-cultural ideology. Basketry-imprint analysis, scanning electron microscopy, and portable X-ray fluorescence suggest that the returned specimen is the original Pilling. After a 40-year absence, it is now permanently curated with the rest of the collection at the Prehistoric Museum, USU Eastern, in Price, Utah, and can contribute to research of a rare artifact class. The techniques reported can also be applied to finds of fragmentary Fremont figurines in secondary contexts to assess relationships among specimens and sites. Most broadly, the successful application of nondestructive pXRF may inspire confidence in scientists studying rare and delicate specimens traditionally profiled using destructive methods such as INAA.