A method and system are described for tracking user activity related to network resources using a browser. The inspection system includes a first robotic inspection vehicle dimensioned to fit in the delivery capsule storage bay and itself defines a storage bay. A gear train is defined along an engine axis. In the caching mechanism, the virtual persistent heap may be divided into cache lines. Some hydrogen is also removed by reaction with the iron oxide, reducing Fe2O3 to FeO, while the remainder of the hydrogen passes through the fluid beds, leaving in a purified state, i. In this invention, a CPU increments a counter value at a clock signal period of a timer when a crane is to be moved down, and decrements the counter value at the clock signal period of the timer when the crane is to be moved up.