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A three-step model for calculating the magnetic field generated by coils inside cuboid-shaped shields like magnetically shielded rooms (MSRs) is presented. The shield is modelled as two parallel plates of infinite width and one tube of…

应用物理 · 物理学 2020-11-17 Tianhao Liu , Allard Schnabel , Jens Voigt , Zhiyin Sun , Liyi Li

The nature of stacking faults - whether intrinsic or extrinsic - plays a pivotal role in defect-mediated processes in crystalline materials. Yet, current electron microscopy techniques for their reliable analysis remain limited to either…

The brightest southern quasar above redshift $z=1$, HE 0515$-$4414, with its strong intervening metal absorption-line system at $z_{abs}=1.1508$, provides a unique opportunity to precisely measure or limit relative variations in the…

宇宙学与河外天体物理 · 物理学 2016-12-07 Srđan M. Kotuš , Michael T. Murphy , Robert F. Carswell

Aims. To obtain limits on the variation of the fine-structure constant alpha and the electron-to-proton mass ratio mu over different cosmological epochs. Methods. A new approach based on the comparison of redshifts of far infrared (FIR)…

天体物理学 · 物理学 2009-09-01 S. A. Levshakov , D. Reimers , M. G. Kozlov , S. G. Porsev , P. Molaro

We derive error estimates of a finite element method for the approximation of solutions to a seven-fields formulation of a magnetohydrodynamics model, which preserves the energy of the system, and the magnetic and cross helicities on the…

数值分析 · 数学 2025-03-04 L. Beirao da Veiga , K. Hu , L. Mascotto

All coronagraphic instruments for exoplanet high-contrast imaging need wavefront correction systems to reject optical aberrations and create sufficiently dark holes. Since the most efficient wavefront correction algorithms (controllers and…

天体物理仪器与方法 · 物理学 2018-10-09 He Sun , N. Jeremy Kasdin , Robert Vanderbei

Abnormal event detection is critical in the safe operation of power system. In this paper, using the data collected from phasor measurement units (PMUs), two methods based on Fisher random matrix are proposed to detect faults in power…

系统与控制 · 电气工程与系统科学 2022-08-10 Ke Chen , Dandan Jiang , Bo Wang , Hongxia Wang

We apply a method recently introduced to the statistical literature to directly estimate the precision matrix from an ensemble of samples drawn from a corresponding Gaussian distribution. Motivated by the observation that cosmological…

天体物理仪器与方法 · 物理学 2016-05-25 Nikhil Padmanabhan , Martin White , Harrison H. Zhou , Ross O'Connell

Context: The detection and characterization of Earth-like exoplanets (exoEarths) from space requires exquisite wavefront stability at contrast levels of $10^{-10}$. On segmented telescopes in particular, aberrations induced by cophasing…

It is demonstrated that finite-pressure, approximately quasi-axisymmetric stellarator equilibria can be directly constructed (without numerical optimization) via perturbations of given axisymmetric equilibria. The size of such perturbations…

等离子体物理 · 物理学 2022-06-22 G. G. Plunk

We present an analysis of 23 absorption systems along the lines of sight towards 18 quasars in the redshift range of $0.4 \leq z_{abs} \leq 2.3$ observed on the Very Large Telescope (VLT) using the Ultraviolet and Visual Echelle…

宇宙学与河外天体物理 · 物理学 2016-03-04 Michael R. Wilczynska , John K. Webb , Julian A. King , Michael T. Murphy , Matthew B. Bainbridge , Victor V. Flambaum

We present evidence for variations in the fine-structure constant from Keck/HIRES spectra of 143 quasar absorption systems over the redshift range 0.2 < z_abs < 4.2. This includes 15 new systems, mostly at high-z (z_abs > 1.8). Our most…

天体物理学 · 物理学 2009-08-18 M. T. Murphy , V. V. Flambaum , J. K. Webb , V. V. Dzuba , J. X. Prochaska , A. M. Wolfe

Traditional Statistical Process Control methodologies face several challenges when monitoring defects in complex geometries, such as those of products obtained via Additive Manufacturing techniques. Many approaches cannot be applied in…

应用统计 · 统计学 2024-04-12 Sara Bonacina , Daniele Zago , Giovanna Capizzi , Bianca Maria Colosimo

We propose a novel approach for estimating the location of block boundaries (change-points) in a random matrix consisting of a block wise constant matrix observed in white noise. Our method consists in rephrasing this task as a variable…

应用统计 · 统计学 2016-03-14 Vincent Brault , Julien Chiquet , Céline Lévy-Leduc

The critical behavior of the Ising model on a fractal lattice, which has the Hausdorff dimension $\log_{4} 12 \approx 1.792$, is investigated using a modified higher-order tensor renormalization group algorithm supplemented with automatic…

统计力学 · 物理学 2023-03-22 Jozef Genzor

In this paper, single-stage stellarator optimization is combined with stochastic coil optimization to improve the robustness of the stellarator as compared to deterministic methods. The plasma boundary, solved with an MHD solver in…

等离子体物理 · 物理学 2026-03-13 Pedro F. Gil , Jason Smoniewski , Rogerio Jorge , Paul Huslage , Eve V. Stenson

We study degeneracies between cosmological parameters and measurement errors from cosmic shear surveys using a principal component analysis of the Fisher matrix. We simulate realistic survey topologies with non-uniform sky coverage, and…

天体物理学 · 物理学 2009-11-13 Dipak Munshi , Martin Kilbinger

We present a method to calibrate wavefront distortion of the spatial light modulator setup by registering far field images of several Gaussian beams diffracted off the modulator. The Fourier transform of resulting interference images…

光学 · 物理学 2016-03-22 Adam Leszczyński , Wojciech Wasilewski

We investigate an additive perturbation of a complex Wishart random matrix and prove that a large deviation principle holds for the spectral measures. The rate function is associated to a vector equilibrium problem coming from logarithmic…

概率论 · 数学 2013-03-14 Adrien Hardy , Arno B. J. Kuijlaars

Identification of the parameters of stable linear dynamical systems is a well-studied problem in the literature, both in the low and high-dimensional settings. However, there are hardly any results for the unstable case, especially…

系统与控制 · 计算机科学 2018-06-06 Mohamad Kazem Shirani Faradonbeh , Ambuj Tewari , George Michailidis