Figure 4.
The utility plot of the attributes in Qingshan scenic spots ((a) utility change with price rating; (b) utility change with activity rating; (c) utility change with service rating).
Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.