Figure 3

An Example of extracting city’s SOI. The figure shows the extraction of 5-SOI and 25-SOI of city A and city B, which are denoted by large blue nodes. The other four cities, W, X, Y, Z, are small yellow nodes, and only the search flows from such four cities to A and B are drawn. The list boxes beside the four nodes are the ranked lists of cities in which W, X, Y, and Z are interested. Note that for simplicity, searches from A and B, or to W, X, Y, Z, are not drawn