A Modification of the Monte Carlo Filtering Approach for Correcting Negative SEA Loss Factors

Abstract

Monte Carlo Filtering (MCF) is one of the methods of Experimental Statistical Energy Analysis (E-SEA), which allows the correction of negative LFs (Loss Factors). In this article, a modification of the MCF method, called DESA (Diagonal Expansion of the Search Area), is proposed. The technique applies a non-uniform extension of the search area when generating a population of normalized energy matrices. The degree of expansion of the search area is controlled by the Diagonal Penalty Factor (DPF). The authors demonstrated the method’s effectiveness on a system that could not be identified in several frequency bands by the classical MCF method. After applying DESA, it was possible to fill in the problematic bands that were missing CLF (coupling loss factor) and DLF (damping loss factor) values. The paper also proposes a way to minimize the errors introduced by using overly high DPF values.

Assessing the Quality of Corrected Negative SEA Loss Factors using TLF criterion

“…Some systems consisted of the same junction but differed in the damping level. The systems discussed in this paper are the same ones that were measured in the previous study [5]. The reader is referred to this previous article in order to find a detailed description of the measurement process.…”

“…The final step is to compute the mean value of the obtained LFs. The MCF proved to be successful in correcting negative loss factors [5], but strong dependence of loss factors value on the so-called search area has been pointed out [6]. This observation raises the question of whether the quality of obtained results is acceptable and physically meaningful.…”

“…This observation raises the question of whether the quality of obtained results is acceptable and physically meaningful. Even though some methods of minimizing MCF errors were proposed in the previous paper [6], the appropriate criterion of loss factors quality is still missing.…”