Abstract: A graphical interface for visually specifying the behavior of combinations of finite-state and continuous-state actors. The state of an actor may be controlled by the states of other actors. The motion of continuous-state actors is constrained by functions represented as, and analogous to, grooves, sockets, pins, glue, springs, and boxes. These functions may be represented graphically on the actor so that the system of constraints is readily ascertainable to the user.

Abstract: A method and apparatus for direct manipulation of 3-D objects on computer display. This method and apparatus provides for a 3-D bounding region wherein the 3-D bounding region has sensitive areas which the user can select with a reference pointer such that when the user manipulates the reference pointer after selecting a sensitive area the 3-D bounding region and the object within it are manipulated with direct kinesthetic correspondence between the user's manipulation of the reference pointer and the bounding region and object manipulation.

Abstract: A miniature laser cavity in which a solid-state lasing gain element and a Q-switch have respective end surfaces at substantially the Brewster angle, parallel to and facing each other, and separated by a narrow gap occupied by a transparent low-index-of-refraction material.

Abstract: An interface module for coupling a VMEbus channel to a Universal Common Data Point channel and exchanging data signals in either direction. The module responds to protocol handshake signals from the originating channel, accepts a multi-word message-block, and provides handshake signals to notify the destination channel of message to be delivered. The module then transfers the message-block to the destination channel.

Abstract: A photovoltaic relay which includes a unique pull down circuit for rapidly turning off the relays field effect transistor(s). The pull down circuit discharges the gate-to-source capacitance of the relay's field effect transistors by turning on a thyristor by turning off a light-activated switch connected between the gate and the cathode terminals of the thyristor. In one integrated circuit embodiment, the light-activated switch is energized by the same light source which activates the photodiode stack which drives the relay. The presence of the pull down circuit does not effect the turn on time of the relay.

Abstract: A polarographic oxygen detection cell of the type having concentric coplanar electrodes. The cell achieves more consistent and predictable operation by using electrode insulators to prevent electrochemical reaction between the areas of high charge density on the cathode and anode conduction disk and those portions of the electrolyte in which increased ion concentration has been attracted by this high charge density, and using the OH.sup.- based electrolyte and a carbon anode so that the reaction at the anode produces gas which can be bled off to avoid altering the composition of the anode or electrolyte.