Recognition of Functional Areas Based on Call Detail Records and Point of Interest Data

Table 3

Discussion of five GASs.

Name	Layer diagram	Discussion
Raster layer		This kind of layer has no difference between cells. In reality, small segmentation makes little significance, but the theoretical basis is insufficient with large divisions. Moreover, this layer crosses the traffic corridor in the city, which may lead to incorrect identification results
Voronoi layer		All units in this layer have irregular sizes, and the accuracy of recognition obviously decreases in areas where the density of mobile base stations is high, making incorrect results more likely in these units. The phenomenon of crossing traffic corridors also exists
Road network segmentation layer		Although this layer does not cross traffic corridors, there is a huge discrepancy in the road network distribution between urban centers and suburbs, which strongly affects the results. Furthermore, the results from this layer lack practical significance
TAZ layer		There is no crossing of traffic corridors in this layer, and the division takes multiple factors into account, such as landform, administration, human history, road network, and urban function. Thus, the results are much more meaningful in terms of traffic field, land use, and urban planning
Administrative layer		The granularity of the division is somewhat coarse, making correct identification difficult. Furthermore, the recognition results are of little significance for urban planning and transportation planning