spectral decomposition is a powerful tool for analysis of seismic data. fourier transform determines the frequency contents of a signal. but for analysis of non-stationary signals, 1-d transform to frequency domain is not sufficient. in early years, transforming of seismic traces into time and frequency domain was done via windowed fourier transform, called a short time fourier transform (stft)...

the analysis of geochemical data in frequency domain, as indicated in this research study, can provide new exploratory informationthat may not be exposed in spatial domain. to identify deep geochemical anomalies, sulfide zone and geochemical noises in dalli cu–au porphyry deposit, a new approach based on coupling fourier transform (ft) and principal component analysis (pca) has beenused. the re...

This paper deals with the robust fault detection(FD) problem in low frequency domain for linear timedelay systems. The H∞ norm and H− index are employed to measure the robustness to unknown inputs and the sensitivity to faults, respectively. The main results include derivation of a sufficient condition for the existence of a robust fault detection observer and a construction of it based on the ...

In this contribution, linearized dynamic model of Cumulative Mass Fraction (CMF) of Potassium Nitrate-Water Seeded Continues Mixed Suspension Mixed Product Removal (CMSMPR) crystallizer is approximated by a simplified model in frequency domain. Frequency domain model simplification is performed heuristically using the frequency response of the derived linearized models data. However, the CM...

Abstract This article studies the Takagi-Sugeno (T-S) fuzzy delayed sampled-data $$\mathcal {H}_\infty $$ H ∞ control problem for a class of intelligent suspension systems with varying vehicle load and frequency-domain constraint. The T-S model is utilized to characteri...

Finding sufficient criteria for synchronization of master-slave chaotic systems by replacing variables control has been an open problem in the field of chaos control. This paper presents some recent works on the subject, with emphasis on chaos synchronization of both identical and parametrically mismatched Lur’e systems by replacing variables control. The synchronization schemes are formally co...

Two seemingly independent streams of control systems research have examined logarithmic sensitivity integrals and limiting linear quadratic optimal control problems. These apparently diverse problems yield some results with an identical right hand side. The main contribution of this paper is to directly explain the commonality between these streams. This explanation involves the use of Parseval...

Recently, much attention has been focused on the generation of optical frequency combs from quantum cascade lasers. We discuss how fast detectors can be used to demonstrate the mutual coherence of such combs, and present an inequality that can be used to quantitatively evaluate their performance. We discuss several technical issues related to shifted wave interference Fourier Transform spectros...