Local deviations of the main field and signal decay due to transverse relaxation lead to perturbations of the Fourier encoding commonly applied in magnetic resonance imaging. Hence, images acquired with trajectories having long readout times suffer from artefacts such as blurring, geometric distortion, and intensity inhomogeneity. These effects can be corrected by means of iterative reconstruct...

Coherence is a fundamental tool in the analysis of neuronal data and for studying multiscale interactions of single and multiunit spikes with local field potentials. However, when the coherence is used to estimate rhythmic synchrony between spiking and any other time series, the magnitude of the coherence is dependent upon the spike rate. This property is not a statistical bias, but a feature o...

In this report, I address 4 different items: (1) the trapping of electrons in a quadrupole field, (2) the electron-cloud build up inside an HER dipole magnet, (3) the closed orbit drift with SVD correction, and (4) the transverse tune shifts and horizontal instability in the HER. The appendix presents preliminary electron-cloud simulations for the two JKJ rings. Geneva, Switzerland May 13, 2002...

In this article, we propose exponentially fitted error correction methods(EECM) which originate from the error correction methods recently developed by the authors (see [10, 11] for examples) for solving nonlinear stiff initial value problems. We reduce the computational cost of the error correction method by making a local approximation of exponential type. This exponential local approximation...

background: small photon fields are increasingly used in modern radiotherapy especially in intensity modulated radiation therapy (imrt) and stereotactic radiosurgery (srs) treatments. accurate beam profile and central axis depth doses measurements of such beams are complicated due to the electron disequilibrium. hence the ebt2 (external beam therapy) gafchromic film was used for dosimetry of sm...

Azimuthal anisotropy or lateral velocity variations cause azimuthal variations in moveout velocity which can lead to seismic image degradation if not properly handled. In cases where apparent azimuthally anisotropic moveout is present, a single picked velocity is inadequate to flatten an event on a 3D CMP gather. Conventional velocity analysis techniques require a significant amount of time and...

Bose and Lin introduced a class of systematic codes for detection of binary asymmetric errors. Later, in [4] this class was generalized and the Generalized Bose-Lin (GBL) codes were introduced. In this note, we describe a Generalized Bose-Lin codes of limited magnitude l. For these codes, the possible undetectable errors are characterized, the undetectable errors of minimum weight are determine...