In the Indian Himalaya, a 15 km stretch of the North Sikkim Highway that is exceptionally susceptible to landsliding is characterized by fine-grained, low permeability debris material. Lanta Khola is one of the major debris slides in this stretch and is active every year during the monsoons....

Hayakawa (1990) has very recently studied the behavior of the power for several large sample tests for the mean direction vector of the Langevin distribution. These tests are not known to possess any non-trivial optimal property. Here we derive some multiparameter locally optimal tests, e.g.,...