High Angular Resolution Diffusion Imaging (HARDI) improved many neurosurgical areas due to its ability to represent complex intra-voxel structures, but is limited for clinical use mainly due to long acquisition times, but also due to noise. To transcend these limits, our work addresses these problems by combining a state-of-the-art multi diffusion tensor model enhanced with spherical ridgelets....

The Fisher-matrix formalism is used routinely in the literature on gravitational-wave detection to characterize the parameter-estimation performance of gravitational-wave measurements, given parametrized models of the waveforms, and assuming detector noise of known colored Gaussian distribution. Unfortunately, the Fisher matrix can be a poor predictor of the amount of information obtained from ...

In this paper we present a multiresolution-based method for period determination that is able to deal with unevenly sampled data. This method allows us to detect superimposed periodic signals with lower signal-to-noise ratios than in classical methods. This multiresolution-based method is a generalization of the wavelet-based method for period detection that is unable to deal with unevenly samp...

The discrete time–frequency matched filter should replicate the continuous time–frequency matched filter. But the methods differ. To avoid aliasing the discrete method transforms the real-valued signal to the complex-valued analytic signal. The theory for the time–frequency matched filter does not consider the discrete case using the analytic signal. We find that the performance of the matched ...

Introduction: In magnetic resonance imaging a tradeoff exists between resolution and the signal to noise ratio (SNR). With any imaging protocol, different fractions of the available scan time could be used to acquire data at higher spatial frequencies (achieving higher resolution) and to perform signal averaging (obtaining greater SNR). A potential way to establish the optimal balance between r...

The Bayesian time-frequency detector operating on spectrogram of non stationary signals is studied. As direct evaluation of the likelihood ratio is impossible, an a priori user parameter called focus is introduced. It is defined as a local time-frequency signal to noise ratio at which the detection is tuned to be optimal. Leading to a unique detection threshold, the parameter introduced is equi...

Self-Mixing (SM) is a promising technique for sensing vibration, distance, velocity etc. To retrieve accurate metric measurements from an acquired SM signal, it is necessary to correctly detect all interferometric fringes. Traditionally, SM fringes are detected by a derivative based threshold (DBT) scheme. However, such a scheme gives correct results only for SM signals with high signalto-noise...

The Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) satellite will be launched in April of 2005, and will make continuous measurements of the Earth's atmosphere for the following three years. Retrieving the spatial and optical properties of clouds and aerosols from the CALIPSO lidar backscatter data will be confronted by a number of difficulties that are not faced i...