A maximum likelihood detector provides improved performance in the presence of multiple user interference, particularly performance of a multiuser receiver for asynchronous CDMA. In one embodiment, the operative electrode has a shape that is different from the array of electrodes. Preferably, the filter is or includes a layer that has been integrated with the sensors by a semiconductor integrated circuit fabrication process. An in-cylinder pressure sensor for detecting an in-cylinder pressure of an engine may be used to determine the presence or absence of the preignition, in the same manner. The invention also provides methods that are useful for managing storm water flow and inhibiting the flow of pollutants, debris, and other contaminants into drainage systems. The capture rate change may be effected gradually to avoid jerks and jumps.