Hiro’omi Tsumura

(Faculty of Culture and Information Science, Doshisha Universit, Japan)

We know that it need scarcely be said again that the 2D drawings have many limits as an archive method of 3D objects and that the 3D point cloud data is not so useful for analysis of typology. The former lacks the Z values (heights or thickness), and the latter lacks the analytics of 3D typology. So, I and collaborator are developing new methods of treating 3D data sets of Archaeological artifacts.
The purposes of this study are to indicate the serviceabilities of 3D points data for examination of archaeological artifacts, to practice this problematic through a case study about the typology of chipped stone tool and to consider our archaeological methodology which we will face in the future.
Until now, many archaeological artifacts were measured with 3D laser scanner as a part of the digital archive methods. Although their systematic or technical engineering studies are increasing, the analytical application of these data in archaeology is not so much.
There are some reasons in this situation, for example, 3D spatial data sets are hard to handle for perception of their shapes by the existing 2D or Euclidean plane geometrical algorithms, and furthermore these data are too big to manage with PC. To apply these data in our archaeological studies’ perspectives, we must introduce new concepts about spatial data sets and create new analytics of artifacts about the typology.
I discuss the 2.5D spatial data sets as an alternative data of 3D data and practice a new typological analysis by using this data in the view of archaeological taxonomy through a case experiment of Neolithic chipped stone tools which were unearthed at Hokkaido, Japan. From this process, I will create the C-index (Configuration index), as a classification coefficient of lithic, the correlations of each attributes were assessed.