A direct spectral phase function calculation method based on spectral phase shifting is described. We show experimentally that the direct phase function calculation method can provide a simple and fast solution in calculating the spectral phase function, while maintaining the same level of accurate measurement capability as that based on the Fourier transform approach.

Fractional Brownian motion (fBm) is a ubiquitous nonstationary model for many physical processes with power-law time-averaged spectra. In this paper, we exploit the nonstationarity to derive the full spectral correlation structure of fBm. Starting from the time-varying correlation function, we derive two different time-frequency spectral correlation functions (the ambiguity function and the Kir...

We analyze the quark spectral function above the critical temperature for deconfinement in quenched lattice QCD using clover improved Wilson fermions in Landau gauge. We show that the temporal quark correlator is well reproduced by a two-pole approximation for the spectral function and analyze the bare quark mass dependence of both poles as well as their residues. In the chiral limit we find th...

Most of the existing techniques for DOA estimation of broadband sources use both spatial and temporal modeling. This may lead to increased complexity besides a large algorithmic delay. In this paper, we propose a technique that employs only spatial information in the form of a single spatial array covariance matrix. Assuming the source to have an ideal bandpass power spectral density, we formul...

Given a separable strongly self-concordant function f : Rn → R, we show the associated spectral function F(X) = ( f ◦ λ )(X) is also strongly self-concordant function. In addition, there is a universal constant O such that, if f (x) is separable self-concordant barrier then O2F(X) is a self-concordant barrier. We estimate that for the universal constant we have O ≤ 22. This generalizes the rela...

This article develops a model of the upstairs market where order size, beliefs, and prices are determined endogenously. We test the model’s predictions using unique data for 5,625 equity trades during the period 1985 to 1992 that are known to be upstairs transactions and are identified as either buyer or seller initiated. We find that price movements prior to the trade date are significantly po...

Prosodic synchrony has been reported to be an important aspect of conversational dyads. In this paper, synchrony in four different dyads is examined. A Time Aligned Moving Average (TAMA) procedure is used to temporally align the prosodic measurements for the detection of synchrony in the dyads. An overlapping windowed correlation procedure is used to measure synchrony for six different prosodic...

We provide variants and improvements of the Brascamp-Lieb variance inequality which take into account the invariance properties of the underlying measure. This is applied to spectral gap estimates for log-concave measures with many symmetries and to non-interacting conservative spin systems.

The effect of dipolar interactions on the spin-wave spectrum of a cubic antiferromagnet is studied. The spinwave spectrum is found to consist of two branches whose frequencies are (ħω)2=(gβ)2[HA+HEa2k2][HA+HE(2−a2k2)−8πM/3+8πM sin2∂k]