Open-channel noise was studied in the large potassium channel of the sarcoplasmic reticulum (SR). Inside-out patches were excised directly from the SR of split skeletal muscle fibers of lobster, with lobster relaxing ringer (LRR) in bath and pipette. The power spectrum of open-channel noise is very low and approximately flat in the 100 Hz-10 kHz frequency range. At 20 degrees C, with an applied...

Using PSD (Power Spectral Density) data on electron density and electric field variations observed on board Aureol-3 satellite at low-to-mid-latitude ionosphere we analyze a scale distribution of the ionospheric turbulence in a form k , where k is the wave number and α is the spectral index. At first, high-resolution data in the near-equator region for several orbits have been processed. In thi...

Power Spectral Density (PSD) of quasi-stationary processes can be efficiently estimated using the short time Fourier series (STFT). In this paper, an algorithm has been proposed that computes the PSD of quasi-stationary process efficiently using offline autoregressive model order estimation algorithm, recursive parameter estimation technique and modified sliding window discrete Fourier Transfor...

The majority of the nonlinearity in a communication system is attributed to the power amplifier (PA) present at the final stage of the transmitter chain. In this paper, we consider Gaussian distributed input signals (such as OFDM), and PAs that can be modeled by memoryless or memory polynomials. We derive closed-form expressions of the PA output power spectral density, for an arbitrary nonlinea...

The angular power spectrum estimator developed by Peebles (1973) and Hauser & Peebles (1973) has been modified and applied to the 4 year maps produced by the COBE DMR. The power spectrum of the observed sky has been compared to the power spectra of a large number of simulated random skies produced with noise equal to the observed noise and primordial density fluctuation power spectra of power l...

INTRODUCTION AND OBJECTIVES The power spectral density can be used to find a hidden behaviour in a physical system. We studied postural behaviour in a healthy population, by means of power spectral density, and compared it with a situation of complete immobility. METHODS A group of healthy volunteers carried out the modified Clinical Test for Sensory Interaction in Balance. A fibre optic gyro...

Introduction and objectives: The power spectral density can be used to find a hidden behaviour in a physical system. We studied postural behaviour in a healthy population, by means of power spectral density, and compared it with a situation of complete immobility. Methods: A group of healthy volunteers carried out the modified Clinical Test for Sensory Interaction in Balance. A fibre optic gyro...

In many hands-free applications, we encounter a speaker located in the near-field embedded in diffuse far-field noise. In this paper, we contribute an algorithm to estimate the speech and noise power spectral density (PSD) based on a directiondependent SNR (DD-SNR). The only prior knowledge needed is a model of the diffuse noise sound field. The enhanced speech signal is obtained by a parametri...

This paper presents a technique for the spectral shaping of roundoff noise in fixed-point implementations of digital filters. An automated feasibility test is introduced, in order to decide whether a given filter realisation meets user-specified constraints on the roundoff noise power spectrum. This feasibility test is used by an algorithm for optimization of individual signal widths within a f...

We analyze the flux power spectrum and its covariance using simulated Lyα forests. We find that pseudo-hydro techniques are good approximations of hydrodynamical simulations at high redshift. However, the pseudo-hydro techniques fail at low redshift because they are insufficient for characterizing some components of the low-redshift intergalactic medium, notably the warm-hot intergalactic mediu...