The invention relates to system and method for generating a 3-dimensional representation of a tunnel. During operation, a cloud controller that maintains a set of metadata for the distributed filesystem receives a request to access a data block for a file. Luminaires incorporating light-emitting devices of this type are also disclosed. Transporting the load is accomplished by providing a pair of rails cantilevered from a stand. The current source is electrically connected to the first and second electrodes and applies a current to the localized region of body tissue to effect iontophoretic transport. A vacuum is created in the interior cavity.