An optical resonator by which reflectivity of ring-down cavity mirrors can be altered and enhanced by adding external optical cavities that recycle light to the main cavity. That allows, the state of the send queues to be taken into consideration when deciding an appropriate order to prefetch data. The steam chamber is closed off at its front and rear ends in the direction of travel by a limiting surface each of which protrudes in the direction toward the material web, and particularly forms a limiting edge; between the limiting surfaces, the steam chamber has a housing wall which is recessed relative to the material web. Lastly, the present invention is also drawn to methods and compositions for increasing the efficacy of the macrocyclic lactone compounds against resistant nematode or resistant arthropod pests which comprise administering to a mammal or applying to crops and the like a pesticidal enhancing effective amount of a multidrug resistance reversing agent. This is compared with an average obtained over a few symbols, to detect impulsive interference, and applied as part of the control for the soft-decision quantizer. This is because, by lowering the bottom energy level of a conduction band of the floating gate electrode than that of the channel formation region in the semiconductor substrate, a carrier injecting property and a charge holding property can be improved.