Direct-sequence code-division multiple-access (DS-CDMA) signals are often regarded as a result of the multiplication of the data bits by a spreading sequence, which is clocked at a higher rate than the data sequence (where the ratio of the rates is the spreading factor), cf. figure 1 a. A conceptually different, but equivalent, description is that the symbol rate is raised by up-sampling (repet...

Purpose Numerous studies report motion as the most detrimental source of noise and artifacts in fMRI. Current correction methods fail to completely address problem. Retrospective techniques such spatial realignment can correct for between-volume misalignment but within volume contamination spin-history artifacts. Prospective prevent currently cannot update gradients fast enough remove k-space f...

Smart antenna technology is a challenging area in the development of wireless communications. Using smart antennas the quality of a radio link can be improved by many ways. Smart antennas are active antenna arrays or groups with changeable complex-valued weights at inputs and outputs. Good electrical matching of the array and the similarity and ideality of element patterns is usually expected. ...

Resting-state data sets contain coherent fluctuations unrelated to neural processes originating from residual motion artefacts, respiration and cardiac action. Such confounding effects may introduce correlations and cause an overestimation of functional connectivity strengths. In this study we applied several multidimensional linear regression approaches to remove artificial coherencies and exa...

Near-infrared spectroscopy (NIRS) is susceptible to signal artifacts caused by relative motion between NIRS optical fibers and the scalp. These artifacts can be very damaging to the utility of functional NIRS, particularly in challenging subject groups where motion can be unavoidable. A number of approaches to the removal of motion artifacts from NIRS data have been suggested. In this paper we ...

The Bright Pixel Atmospheric Correction (BPAC) is the MERIS operational algorithm for precorrecting the residual marine signal in the near infrared prior to the Clear water atmospheric correction. It is an essential step in the mission for computing Level 2 products on Case 2 waters. It is also always applied on Case 1 waters. The method is based on an iterative coupling between a simplified at...

Numerical simulations of atmospheric turbulence and AO wavefront correction are performed to investigate the timescale for fringe motion in optical interferometers with spatial filters. These simulations focus especially on partial AO correction, where only a finite number of Zernike modes are compensated. The fringe motion is found to depend strongly on both the aperture diameter and the level...

Helical structures are more disordered and diffract more weakly than two-dimensional crystals, and images of them are inherently noisier. Automated techniques allowed us to correct, align and merge data from hundreds of images. To extend from ~1.0 nm resolution to the near atomic level (~0.4 nm), we needed to know whether our handling of images could be improved. For example, curved particles a...

Network properties can be estimated using functional connectivity MRI (fcMRI). However, regional variation of the fMRI signal causes systematic biases in network estimates including correlation attenuation in regions of low measurement reliability. Here we computed the spatial distribution of fcMRI reliability using longitudinal fcMRI datasets and demonstrated how pre-estimated reliability maps...

During cell division, aberrant DNA structures are detected by regulators called checkpoints that slow division to allow error correction. In addition to checkpoint-induced delay, it is widely assumed, though rarely shown, that merely slowing the cell cycle might allow more time for error detection and correction, thus resulting in a more stable genome. Fidelity by a slowed cell cycle might be i...