We present a versatile illumination system where white light emitting diodes are coupled through a planar waveguide to periodically patterned extraction features at the focal plane of a two dimensional lenslet array. Adjusting the position of the lenslet array allows control over both the directionality and divergence of the emitted beam. We describe an analytic design process, and show optimal...

background and aims. at present, cone beam computed tomography (cbct) has become a substitute for computed tomography (ct) in dental procedures. the metallic materials used in dentistry can produce artifacts due to the beam hardening phenomenon. these artifacts decrease the quality of images. in the present study, the number of artifacts as a result of beam hardening in the images of dental imp...

A least-squares linear fixed-interval smoothing algorithm is derived to estimate signals from uncertain observations perturbed by additive white noise. It is assumed that the Bernoulli variables describing the uncertainty are only correlated at consecutive time instants. The marginal distribution of each of these variables, specified by the probability that the signal exists at each observation...

Abstract A multi-beam X-ray optical system using a σ-polarization diffraction geometry is proposed and its potential for high-speed tomography synchrotron radiation experimentally evaluated. Projection images of sample are obtained simultaneously from different directions with beams generated by white beam at silicon single crystals. This makes it possible to record tomographic dataset without ...

in investigation of dynamic specifications of castellated beams, it is necessary to be studied the excitation intensity of dynamic mode shapes for different loading conditions. it is evident that for a specific loading, not all modes of a structure are excited and the structural response depends on the applied loading specifications. in this paper using the finite element method (based on ansys...