We have observed that Vibroseis wavelets behave very much as if they are minimum phase. This was discovered by applying minimum-phase Wiener deconvolution to the separated vibroseis VSP downgoing waves and observing that the result is effectively a band-limited spike. Motivated by this finding, we simulated a synthetic nonstationary vibroseis wavelet in a constant-Q medium by nonstationary conv...

We review the advancement of nonstationary time series analysis from the perspective of Cowles Commission structural equation approach. We argue that despite the rich repertoire nonstationary time series analysis provides to analyze how do variables respond dynamically to shocks through the decomposition of a dynamic system into long-run and short-run relations, nonstationarity does not invalid...

We present an iterative scheme based on the fixed point approximation method, for the numerical calculation of the time-dependent mean number of customers and blocking probability functions in a nonstationary queueing network with multi-rate loss queues. We first show how the proposed method can be used to analyze a single-class, multiclass, and multi-rate nonstationary loss queue. Subsequently...

Sensor arrays are able to enhance desired signal reception while simultaneously suppressing undesired components through the use of directionality. In many important applications, the return signal is best modeled as being nonstationary and may lose coherence between sensors, severely limiting the performance of traditional array processors based on matched-field beamforming. Quadratic array pr...

axial distributions of plasma and floating potentials, electron number density and the electron energy distribution function (eedf) have been measured in the double layer (dl) region of an he discharge constriction. excitation processes in the constriction region are studied. using a linearization method for the nonstationary balance equations and choosing appropriate discharge conditions, the ...

This paper proposes a class of new nonlinear threshold autoregressive models with both stationary and nonstationary regimes. Existing literature basically focuses on testing for a unit–root structure in a threshold autoregressive model. Under the null hypothesis, the model reduces to a simple random walk. Parameter estimation then becomes standard under the null hypothesis. How to estimate para...

Swelling-induced loss of organic osmolytes from cells is mediated by an outwardly rectified, volume-sensitive anion channel termed VSOAC (Volume-Sensitive Organic osmolyte/Anion Channel). Similar swelling-activated anion channels have been described in numerous cell types. The unitary conductance and gating kinetics of VSOAC have been uncertain, however. Stationary noise analysis and single-cha...

Previous analysis of high frequency nancial time series data has found volatility to follow a long-memory process and to display an intradaily U-shape pattern. These ndings implicitly assume that a stable environment exists in the nancial world. To better capture the nonstationary behavior associated with market collapses, political upheavals and news annoucements, we propose a nonstationary cl...

The generalized Langevin equation (GLE) is extended to the case of nonstationary bath. The derivation starts with the Hamiltonian equation of motion of the total system including the bath, without any assumption on the form of Hamiltonian or the distribution of the initial condition. Then the projection operator formulation is utilized to obtain a low-dimensional description of the system dynam...

Multisensor array processing of noisy measurements has received considerable attention in many areas of signal processing. The optimal processing techniques developed so far usually assume that the signal and noise processes are at least wide sense stationary, yet a need exists for efficient, effective methods for processing nonstationary signals. Although wavelets have proven to be useful tool...