The electronic circuit breaker comprises an input for connection to a power-supply network and an output for connection to a load. Such scope correction apparatus receives light from a scene that is located a relatively short distance from the scope such that, without the presence of the scope correction apparatus, the focal point of the light within the scope would not be overlaid with the scope reticle. The methods include the addition of the lanthanide compounds to the bulk of the pool water, but preferably involve the loading of the pool filter with the composition and the circulation of pool water through the filter to effect the removal of dissolved phosphate in the water. Modifying the dither signals in this matter allows moving actuators at a rate that is much closer to the natural frequency of the underlying system, and hence speeds up the system convergence process. To accommodate a frustum bucket with changing wall diameter, the skirt flexes resiliently with the flange engaging the bucket wall and the skirt flexing inward as the screen is inserted in a bucket with decreasing diameter. The first module estimates a total amount of exhaust gas recirculation in the engine, wherein the total amount of EGR includes EGR within cylinders of the engine and EGR flowing through an EGR system of the engine.