An IoT-Enabled Early Warning System for Landslides and Acid Rain Through Rainfall and pH Monitoring. - Phu Nguyen Van; Phuc Dao Anh; Dat Nguyen Tien; Minh Nguyen Viet; Mai Huong Nguyen Thi; Kien Do Trung; Thanh Pham Van (KSII Trans. Internet Inf. Syst., 2025)