32,495 research outputs found
Direct 3D Tomographic Reconstruction and Phase-Retrieval of Far-Field Coherent Diffraction Patterns
We present an alternative numerical reconstruction algorithm for direct
tomographic reconstruction of a sample refractive indices from the measured
intensities of its far-field coherent diffraction patterns. We formulate the
well-known phase-retrieval problem in ptychography in a tomographic framework
which allows for simultaneous reconstruction of the illumination function and
the sample refractive indices in three dimensions. Our iterative reconstruction
algorithm is based on the Levenberg-Marquardt algorithm. We demonstrate the
performance of our proposed method with simulation studies
OPED reconstruction algorithm for limited angle problem
The structure of the reconstruction algorithm OPED permits a natural way to
generate additional data, while still preserving the essential feature of the
algorithm. This provides a method for image reconstruction for limited angel
problems. In stead of completing the set of data, the set of discrete sine
transforms of the data is completed. This is achieved by solving systems of
linear equations that have, upon choosing appropriate parameters, positive
definite coefficient matrices. Numerical examples are presented.Comment: 17 page
A Fast Reconstruction Algorithm for Gene Networks
This paper deals with gene networks whose dynamics is assumed to be generated
by a continuous-time, linear, time invariant, finite dimensional system (LTI)
at steady state. In particular, we deal with the problem of network
reconstruction in the typical practical situation in which the number of
available data is largely insufficient to uniquely determine the network. In
order to try to remove this ambiguity, we will exploit the biologically a
priori assumption of network sparseness, and propose a new algorithm for
network reconstruction having a very low computational complexity (linear in
the number of genes) so to be able to deal also with very large networks (say,
thousands of genes). Its performances are also tested both on artificial data
(generated with linear models) and on real data obtained by Gardner et al. from
the SOS pathway in Escherichia coli.Comment: 12 pages, 3 figure
Validity of using the Sheffield algorithm for the Sussex EIT MK4
This paper introduces the image reconstruction algorithm from Sheffield group and the validity of this algorithm to the Sussex MK4
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