http://reply.papertrans.cn/3/297/29688/29688-31.png
http://reply.papertrans.cn/3/297/29688/29688-32.png
Submitted on: 23 January 2021.
Revised on: 17 February 2021.
Accepted on: 14 March 2021.
Transactions in GIS
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http://reply.papertrans.cn/3/297/29688/29688-35.png
http://reply.papertrans.cn/3/297/29688/29688-36.png