Abstract
The spatial scan statistic is a method of detection and inference for the zones of significantly high or low rates based on the likelihood ratio. Kulldorff (1997) detected the hotspots based on spatial scan statistic with Binomial and Poisson models. The circular window zone for scanning is defined around one cellular (county) seat. The zone consists of counties whose county seat exists within the circle. Thus this approach has the properties to find the circular cluster as the candidate of hotspots. The echelon (Myers et al., 1997) is useful technique to study the topological structure of a surface in the systematic and objective manner. The echelon dendrogram represents the surface topology of cellular data and hierarchical structure of these data. The candidates of hotspots are given as the top echelon in the dendrogram. The purpose of this paper is to detect the any shapes of hotspots based on echelon analysis and spatial scan statistics. We demonstrate the procedure to find the hotspots based on newly proposed technique for sudden infant death syndrome (SIDS) data for each of the counties of North Carolina for the periods of 1974-1984. We also detect the hotspots of cells for r × c two-way ordered categorical data in contingency table with the example.
