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We continue to develop the method for creation and annihilation of contour singularities in the $\bar\partial$--spectral data for the two-dimensional Schr\"odinger equation at fixed energy. Our method is based on the Moutard-type transforms…

Mathematical Physics · Physics 2019-11-22 P. G. Grinevich , R. G. Novikov

An efficient computational approach for optimal reconstruction of binary-type images suitable for models in various applications including biomedical imaging is developed and validated. The methodology includes derivative-free optimization…

Optimization and Control · Mathematics 2022-09-27 Paul R. Arbic , Vladislav Bukshtynov

A momentum-space approach of the density-matrix renormalization-group (DMRG) method is developed. Ground state energies of the Hubbard model are evaluated using this method and compared with exact diagonalization as well as quantum…

Condensed Matter · Physics 2009-10-28 T. Xiang

Performing magnetic resonance imaging (MRI) reconstruction from under-sampled k-space data can accelerate the procedure to acquire MRI scans and reduce patients' discomfort. The reconstruction problem is usually formulated as a denoising…

Image and Video Processing · Electrical Eng. & Systems 2023-12-11 Tianqi Xiang , Wenjun Yue , Yiqun Lin , Jiewen Yang , Zhenkun Wang , Xiaomeng Li

Electron tomography is a technique used in both materials science and structural biology to image features well below optical resolution limit. In this work, we present a new algorithm for reconstructing the three-dimensional(3D)…

Signal Processing · Electrical Eng. & Systems 2018-07-12 David Ren , Michael Chen , Laura Waller , Colin Ophus

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…

Computational Physics · Physics 2019-02-06 T. Ramos , Bastian E. Grønager , Martin Skovgaard Andersen , J. W. Andreasen

Physically reasonable electronic structures of reconstructed rutile TiO_2(110)-(1x2) surfaces were studied using density functional theory (DFT) supplemented with Hubbard U on-site Coulomb repulsion acting on the d electrons, so called as…

Strongly Correlated Electrons · Physics 2016-08-14 Hatice Ünal , Ersen Mete , Şinasi Ellialtioğlu

A direct method is proposed for reconstruction of the effective atomic number by means of multi-energy radiography of the material. The accuracy of the method is up to 95% . Advantages over conventional radiographic methods, which ensure…

Accelerator Physics · Physics 2009-11-10 Sergey V. Naydenov , Vladimir D. Ryzhikov , Craig F. Smith

In this paper, it is shown that an auto-encoder using optimal reconstruction significantly outperforms a conventional auto-encoder. Optimal reconstruction uses the conditional mean of the input given the features, under a maximum entropy…

Machine Learning · Computer Science 2021-04-16 Paul M Baggenstoss

We propose Dirichlet Winding Reconstruction (DiWR), a robust method for reconstructing watertight surfaces from unoriented point clouds with non-uniform sampling, noise, and outliers. Our method uses the generalized winding number (GWN)…

Computer Vision and Pattern Recognition · Computer Science 2026-02-17 Jiaze Li , Daisheng Jin , Fei Hou , Junhui Hou , Zheng Liu , Shiqing Xin , Wenping Wang , Ying He

A numerical renormalization group technique recently developed by one of us is used to analyse the Coulomb pseudopotential (${\mu^*}$) in ${{\rm C}_{60}}$ for a variety of bare potentials. We find a large reduction in ${\mu^*}$ due to…

Condensed Matter · Physics 2009-10-22 Nikos Berdenis , Ganpathy Murthy

We present the first numerical approach to D-bar problems having spectral convergence for real analytic rapidly decreasing potentials. The proposed method starts from a formulation of the problem in terms of an integral equation which is…

Numerical Analysis · Mathematics 2015-08-11 C. Klein , K. McLaughlin

In practice of acoustic tomography, for example, in medical applications and ocean tomography, the relative deviation of sound speed from its background value usually does not exceed 10-30%. At the same time, in electromagnetic…

Numerical Analysis · Mathematics 2024-01-26 A. S. Shurup

For a compact connected Riemannian manifold with smooth boundary, we establish an effective procedure, by which we can calculate all the coefficients of the spectral asymptotic formula of the Dirichlet-to-Neumann map associated to the…

Differential Geometry · Mathematics 2025-01-14 Xiaoming Tan

We present an approach to accelerate real-space electronic structure methods several fold, without loss of accuracy, by reducing the dimension of the discrete eigenproblem that must be solved. To accomplish this, we construct an efficient,…

Computational Physics · Physics 2018-05-01 Qimen Xu , Phanish Suryanarayana , John E. Pask

No systematic procedure currently exists for inferring the underlying physics from discrepancies observed in high energy collider data. We present Bard, an algorithm designed to facilitate the process of model construction at the energy…

High Energy Physics - Phenomenology · Physics 2007-05-23 Bruce Knuteson , Stephen Mrenna

A new approach to nonperturbative calculations in quantum electrodynamics is proposed. The approach is based on a regular iteration scheme for solution of Schwinger-Dyson equations for generating functional of Green functions. The approach…

High Energy Physics - Phenomenology · Physics 2008-11-26 V. E. Rochev

In Electrical Impedance Tomography (EIT) one wants to image the conductivity distribution of a body from current and voltage measurements carried out on its boundary. In this paper we consider the underlying mathematical model, the inverse…

Numerical Analysis · Mathematics 2017-04-10 Andreas Hauptmann , Matteo Santacesaria , Samuli Siltanen

In this paper, we propose a new spectral decomposition method to simulate waves propagating in complicated waveguides. For the numerical solutions of waveguide scattering problems, an important task is to approximate the…

Numerical Analysis · Mathematics 2022-07-27 Ruming Zhang

An electrical potential U on bordered surface X (in Euclidien three-dimensional space) with isotropic conductivity function sigma>0 satisfies equation d(sigma d^cU)=0, where d^c is real operator associated with complex (conforme) structure…

Analysis of PDEs · Mathematics 2011-07-08 Gennadi Henkin , Roman Novikov