English
Related papers

Related papers: Sparse Modeling analysis of Extended X-ray Absorpt…

200 papers

Oscillatory structure is found in the atomic background absorption in x-ray-absorption fine structure (XAFS). This atomic-XAFS or AXAFS arises from scattering within an embedded atom, and is analogous to the Ramsauer-Townsend effect.…

Condensed Matter · Physics 2009-10-22 J. J. Rehr , C. H. Booth , F. Bridges , S. I. Zabinsky

This paper investigates near-field XL-MIMO systems with sparse uniform planar arrays (UPAs). Based on the Green's function-based channel model, the paper derives closed-form expressions for the signal beam power when the distance coordinate…

Signal Processing · Electrical Eng. & Systems 2025-10-16 Xianzhe Chen , Hong Ren , Cunhua Pan , Cheng-Xiang Wang , Jiangzhou Wang

A Bayesian method application to the deconvolution of EXAFS spectra is considered. It is shown that for purposes of EXAFS spectroscopy, from the infinitely large number of Bayesian solutions it is possible to determine an optimal range of…

Data Analysis, Statistics and Probability · Physics 2009-11-07 K. V. Klementev

Widely employed Near-Edge X-Ray Absorption Fine Structure (NEXAFS) spectroscopy probes a system by excitation of core electrons to unoccupied states. A variety of different methodologies are available to simulate corresponding spectra from…

Chemical Physics · Physics 2019-02-14 Georg S. Michelitsch , Karsten Reuter

A novel method and experimental configuration are proposed that allow the collection of high-quality X-ray absorption spectroscopy (XAS) data in transmission mode on a standard laboratory diffractometer. This configuration makes use of…

Instrumentation and Detectors · Physics 2025-09-23 Milen Gateshki , Charalampos Zarkadas , Detlef Beckers

The interference between extrinsic and intrinsic losses in x-ray absorption fine structure (XAFS) is treated within a Green's function formalism, without explicit reference to final states. The approach makes use of a quasi-boson…

Materials Science · Physics 2007-05-23 L. Campbell , L. Hedin , J. J. Rehr , W. Bardyszewski

In disordered materials under mechanical stress, the produced deformation can deviate from the affine one already in the elastic regime. The nonaffine contribution was observed and characterized in numerical simulations for various systems.…

Soft Condensed Matter · Physics 2021-12-17 Alesya Mikhailovskaya , Julien Fade , Jérôme Crassous

Dual-energy imaging is a clinically well-established technique that offers several advantages over conventional X-ray imaging. By performing measurements with two distinct X-ray spectra, differences in energy-dependent attenuation are…

Material decomposition in X-ray imaging uses the energy-dependence of attenuation to virtually decompose an object into specific constituent materials. X-ray phase contrast imaging is a developing technique that can enhance image contrast…

Phase transitions of solids and structural transformations of molecules are canonical examples of important photo-induced processes, whose underlying mechanisms largely elude our comprehension due to our inability to correlate electronic…

An approach is presented for theoretical calculations of the Debye-Waller factors in x-ray absorption spectra. These factors are represented in terms of the cumulant expansion up to third order. They account respectively for the net thermal…

Materials Science · Physics 2009-11-13 Fernando D. Vila , J. J. Rehr , H. H. Rossner , H. J. Krappe

X-ray absorption spectroscopy yields direct access to the electronic and geometric structure of hybrid inorganic-organic interfaces formed upon adsorption of complex molecules at metal surfaces. The unambiguous interpretation of…

Chemical Physics · Physics 2017-06-19 Katharina Diller , Reinhard J. Maurer , Moritz Müller , Karsten Reuter

The near edge structure (XANES) in K-edge X-ray absorption spectroscopy (XAS) is a widely used tool for studying electronic and local structure in materials. The precise interpretation of these spectra with the help of calculations is hence…

Energy dispersive X-ray (EDX) spectrum imaging yields compositional information with a spatial resolution down to the atomic level. However, experimental limitations often produce extremely sparse and noisy EDX spectra. Under such…

A new statistical model designed for regression analysis with a sparse design matrix is proposed. This new model utilizes the positions of the limited non-zero elements in the design matrix to decompose the regression model into…

Applications · Statistics 2022-01-17 Hsien-Wei Chen

We propose a method for recovering the structure of a sparse undirected graphical model when very few samples are available. The method decides about the presence or absence of bonds between pairs of variable by considering one pair at a…

Machine Learning · Statistics 2017-01-03 Nicola Bulso , Matteo Marsili , Yasser Roudi

This paper addresses the problem of expressing a signal as a sum of frequency components (sinusoids) wherein each sinusoid may exhibit abrupt changes in its amplitude and/or phase. The Fourier transform of a narrow-band signal, with a…

Machine Learning · Computer Science 2013-02-27 Yin Ding , Ivan W. Selesnick

Bayesian sparse factor models have proven useful for characterizing dependence in multivariate data, but scaling computation to large numbers of samples and dimensions is problematic. We propose expandable factor analysis for scalable…

Methodology · Statistics 2018-06-21 Sanvesh Srivastava , Barbara E. Engelhardt , David B. Dunson

In this paper, we propose a Bayesian spectral deconvolution considering the properties of peaks in different energy domains. Bayesian spectral deconvolution regresses spectral data into the sum of multiple basis functions. Conventional…

Pre-edge features in X-ray absorption spectroscopy contain key information about the lowest excited states and thus on the most interesting physical properties of the system. In transition metal oxides they are particularly structured but…

Materials Science · Physics 2008-07-01 C. Gougoussis , M. Calandra , A. Seitsonen , Ch. Brouder , A. Shukla , F. Mauri