Right after its invention in the late nineties, Frequency Domain Decomposition (FDD) identification technique became very popular operational modal analysis community due to simplicity and robustness. The underlying idea of this consists computing singular value decomposition Power Spectral Densities (PSDs) estimated from measured vibration responses with periodogram (also known as “Welch’s”) a...

obtaining a seismic section with high temporal and spatial resolution was always one of the goals of seismic data processors and interpreters. accurate estimation of the thicknesses of thin beds is an important tool in this regard. the basic problem is that the wavelength of the signal must be similar in dimention to that of the bed thinness. if it is much longer than the bed thinness, the dete...

This paper proposes a voice decomposition method based on voice model. Using correlation distance as a criterion frequency domain decomposition is formulated. For a pair of correlation coe cient vectors minimizing powers of spectra is characterized using quadratic programming problem with constraint, where values of powers are non-negative. The solution of the problem without constraint is calc...

The following study deals with the updating the finite element model of structures using the operational modal analysis. The updating process uses an evolutionary optimization algorithm, namely bees algorithm which applies instinctive behavior of honeybees for finding food sources. To determine the uncertain updated parameters such as geometry and material properties of the structure, local and...

This contribution reviews the external and the internal representations of linear time-invariant systems. This is done both in the time and the frequency domains. The realization problem is then discussed. Given the importance of norms in robust control and model reduction, the final part of this contribution is dedicated to the definition and computation of various norms. Again, the interplay ...

The output data from a structure is the building block for output-only modal analysis. The structure response in the output data, however, is usually contaminated with noise. Naturally, the success of output-only methods in determining the modal parameters of a structure depends on noise level. In this paper, the possibility and accuracy of identifying the modal parameters of a simply supported...

SINGLE-CARRIER FREQUENCY DOMAIN EQUALIZATION USING SUBBAND DECOMPOSITION FOR OPTICAL WIRELESS COMMUNICATIONS by Di Mu Optical wireless communication is intended to be applied into indoor and visual distance high-rate data transmission, which is complementary to radio frequency communications. There are specific problems and requirements in optical wireless communications compared with radio fre...

helicopter-borne electromagnetic (hem) is a fast and high resolution airborne electromagnetic (aem) method that is frequently used for imaging of the subsurface resistivity structures. this is a versatile and cost effective method, frequently has used in mineral and groundwater exploration and various environmental problems. modern frequency-domain hem systems utilize small electromagnetic, mag...