For a sample of n independent identically distributed p-dimensional centered random vectors with covariance matrix Σn let S̃n denote the usual sample covariance (centered by the mean) and Sn the non-centered sample covariance matrix (i.e. the matrix of second moment estimates), where p > n. In this paper, we provide the limiting spectral distribution and central limit theorem for linear spectral...

The influence of spectral inversion on the phase jitter of a soliton propagating in single-channel arbitrary dispersion-managed systems is studied with a semianalytic moment method. The results are similar to those previously observed in constant-dispersion links and show that the transmission-system reach can significantly be increased. © 2006 Optical Society of America OCIS codes: 060.0060, 0...

Responses of Gabor wavelets in the mid-frequency space build a local spectral representation scheme with optimal properties regarding the time-frequency uncertainty principle. However, when using Gabor wavelets we observe a skewness in the mid-frequency space caused by the spreading effect of Gabor wavelets. Though in most current applications the skewness does not obstruct the sampling of the ...

[1] We have studied solar variations during the Holocene (i.e., last 11,700 yr) by combining a new model of the Earth’s dipole moment with C data from the IntCal04 record and Be data from the GRIP ice core. Joint spectral analysis of the two nuclide records suggests that the periodic behavior of the Sun was particularly pronounced between 6000–4500 yr BP and 3000–2000 yr BP, with dominating per...

The mixed-ligand complexes of various metal(II) with 5-chloro-7-iodo-8-hydroxyquinoline (Clioquinol) and 5-(methoxymethyl-8-quinolinol) (MMQ) were prepared. The structure of mixed-ligand complexes was investigated using spectral, physicochemical, elemental analyses and thermal studies. Magnetic moment and reflectance spectral studies reveal that an octahedral geometry has been assigned to all t...

In this paper, a method for the digital simulation of wind velocity fields by Fractional Spectral Moment function is proposed. It is shown that by constructing a digital filter whose coefficients are the fractional spectral moments, it is possible to simulate samples of the target process as superposition of Riesz fractional derivatives of a Gaussian white noise processes. The key of this simul...

Power-spectral analyses of the intensity of Earth’s magnetic field inferred from ocean sediment cores and archeomagnetic data from time scales of 100 yr to 10 Myr have been carried out. The power spectrum is proportional to 1rf where f is the frequency. These analyses compliment previous work which has established a 1rf 2 spectrum for variations at time scales less than 100 yr. We test the hypo...

This paper explores the relationship between Toeplitz and circulant matrices. Upper and lower bounds for all eigenvalues of hermitian Toeplitz matrices are given, capitalizing on the possibility of embedding a Toeplitz matrix in a circulant, and of expressing any nn Toeplitz matrix as a sum of two matrices with known eigenvalues. The bounds can be simultaneously found using a single discrete Fo...

When a mixture of sound from many sources arrives at the ear, the auditory system attempts to segregate it into different perceptual streams. For sequences of sounds, the effects of basic acoustic properties (e.g., frequency separation, rate) on streaming are well understood, but much less is known about the effects of more complex acoustic attributes. Dynamic variations in frequency spectrum a...

The Fourier transform usually has been used in the past for analysis of stationary and periodic signals. Its interest is the knowledge of spectral components existing in a waveform; it doesn't matter the moment where they happen. However, when the time localization of the spectral components is needed, the Wavelet Transform (WT) can be used to obtain the optimal timefrequency representation of ...