An increasing number of underwater gliders have been applied to lake monitoring. Lakes have a limited vertical space. Therefore, good space-saving capacity is required for underwater gliders to enlarge the spacing between monitoring waypoints. This paper presents a space-saving steering method under a small pitch angle (SPA) for appearance-fixed underwater gliders. Steering under an SPA increases the steering angle in per unit vertical space. An amended hydrodynamic model for both small and large attack angles is presented to help analyze the steering process. Analysis is conducted to find the optimal parameters of net buoyancy and roll angle for steering under an SPA. A lake trial with a prototype tiny underwater glider (TUG) is conducted to inspect the applicability of the presented model. The trial results show that steering under an SPA saves vertical space, unlike that under a large pitch angle. Simulation results of steering are consistent with the trial results. In addition, multiple-waypoint trial shows that monitoring with steering under an SPA covers a larger horizontal displacement than that without steering.

The continuous reduction of the device size in integrated circuits and the increase in the switching rate cause parasitic capacitances between conducting layers to become dominant and cause logic errors in the circuits. Therefore, capacitive couplings can be considered as potential logic faults. Classical fault models do not cover this class of faults. This paper presents a logic level characterization and fault model for crosstalk faults. The authors also show how a fault list of such faults can be generated from the layout data, and give an automatic test pattern generation procedure for them.>