Abstract: An adaptive sequential wavefront sensor comprises a sub-wavefront focusing lens, a sequential wavefront scanning device, a variable aperture, a position sensing device, and means for coordinating the operation of the wavefront scanning device, the variable aperture and the position sensing device. An adaptive sequential wavefront sensing method comprises the steps of sequentially projecting portions of a wavefront as image spots on a position sensing device, determining the deflection of each received image spot from a reference point on the position sensitive device, and coordinating the operation of a variable aperture with the operation the sequential projection and image position sensing. The adaptive sequential wavefront sensor has high speed, large dynamic range and variable spatial resolution, and hence can be used for real time measurement of the dynamics of eye accommodation.

Abstract: In one embodiment, separate rate meters are maintained for each flow enqueued an increased at a target rate while a packet from the flow occupies the head of a shared transmit queue. The meter value is decreased by the packet length when a packet in enqueued or dropped. The next packet that occupies the head of the shared transmit queue is dropped if the meter value corresponding to the flow is greater than a threshold.

Abstract: A fault-tolerant stack of low cost switches each having only two dual-purpose uplinks is enabled by utilizing a specified topology for connecting the uplinks and implementing a recovery algorithm on each switch.