This study investigates how different form-focused instruction (FFI) timing impacts English as a foreign language (EFL) learners’ grammar development. A total of 169 Chinese middle school learners were assigned to four conditions randomly: control, before-isolated FFI, integrated and after-isolated FFI. The three experimental groups received treatments which combined form meaning with the passi...

Achieving persistent autonomy requires unmanned surface vehicles (USVs) to be able to deal with a wide variety of complex planning situations. In this paper, we introduce a model-predictive, local trajectory planning algorithm for USVs operating in congested and highly dynamic traffic. The planner generalizes the Velocity Obstacle concept to systems with non-linear dynamics, nonholonomic constr...