Signal Processing Method by Introducing Fuzzy Theory and Its Application to Electromagnetic and Sound Environments

In general, analyses of phenomena in an electromagnetic and sound environments showing various types of complex fluctuation form can be classified into two categories. One is the analysis method from the bottom-up viewpoint, and the other is the method based on the top-down viewpoint. The former is a method structurally based on the physical mechanism existing in the phenomena. The latter method lays the stress on a functional viewpoint connected with the human response to environmental phenomena, in order to obtain an evaluation of the phenomena even in cases of an unknown or uncertain structural mechanism. In this study, from the latter viewpoint, we propose a signal processing method utilizing fuzzy theory to be applied to actual electromagnetic and sound environmental phenomena. The validity of the proposed method is experimentally confirmed by applying it to observed electromagnetic and sound data in the actual working environments, as two typical examples of phenomena difficult to partition into crisp sets by means of a threshold.