We study crossover phenomena in a model of self-avoiding walks with medium-range jumps, which corresponds to the limit N-->0 of an N-vector spin system with medium-range interactions. In particular, we consider the critical crossover limit that interpolates between the Gaussian and the Wilson-Fisher fixed point. The corresponding crossover functions are computed by using field-theoretical metho...

The dynamic range of holographic storage media is traditionally characterized in terms of M/#. However, this is a system parameter that assumes simple, uniform plane-wave holograms. Realistic architectures violate this assumption so that M/# measured with plane waves cannot be used to predict system diffraction efficiency. Thus, there currently is no systematic method predicting signal strength...

Based on analyzing and synthesizing the effects of In doping, Fe doping and oxidation state, we propose an efficient way to improve photorefractive properties of LiNbO3 crystal. According to the proposed way, a sample of In:Fe:LiNbO3 crystal is grown and achieves larger dynamic range, higher sensitivity and better signal-to-noise ratio thanFe:LiNbO3 crystal (Fe:0.03wt.%) that is generally consi...

Digital image archival requires less physical storage space, allows for rapid storage and retrieval and avoids loss in image quality over time or with image duplication compared with film storage. Because medical imaging data are critically important and, by law, must be stored in a safe, accessible manner, it is imperative not to have one computer error destroy all copies of the image data. Se...