A user contracts for service with an operations center in order to provide monitoring and tracking services for a plurality of devices. As a method for equalization that satisfies causality, a least mean square algorithm is applied to the partial response waveform generated as described above. The arrangement permits modification of gas delivery arrangements to meet the needs of a particular processing regime. The invention particularly relates to a xenograft animal model for hosting and propagating human papillomavirus, thereby providing a means for generating infectious and passaging HPV suspensions, and for screening candidate therapeutic agents against HPV. , Tsn, the brightness of light emitted by the EL elements during at least one sustain period is set to be always lower than the brightness of light emitted by the EL elements during the other sustain periods, and the sustain periods are extended by the amount that the brightness has dropped.