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We study the inverse medium scattering problem to reconstruct the unknown inhomogeneous medium from the far-field patterns of scattered waves. The inverse scattering problem is generally ill-posed and nonlinear, and the iterative…

Analysis of PDEs · Mathematics 2022-08-31 Takashi Furuya , Roland Potthast

Many nonlinear differential equations arising from practical problems may permit nontrivial multiple solutions relevant to applications, and these multiple solutions are helpful to deeply understand these practical problems and to improve…

Optimization and Control · Mathematics 2025-04-17 Lin Li , Yuheng Zhou , Pengcheng Xie , Huiyuan Li

Accurate extrinsic calibration of multiple LiDARs is crucial for improving the foundational performance of three-dimensional (3D) map reconstruction systems. This paper presents a novel targetless extrinsic calibration framework for…

Robotics · Computer Science 2025-07-15 Han Ye , Yuqiang Jin , Jinyuan Liu , Tao Li , Wen-An Zhang , Minglei Fu

We propose a Riemannian limited-memory BFGS method for optimization problems with Euclidean bounds. The method combines a limited-memory quasi-Newton update in the tangent space with a Riemannian adaptation of the generalized Cauchy point…

Optimization and Control · Mathematics 2026-05-12 Mateusz Baran , Ronny Bergmann , Patryk Przybysz

Stochastic variance reduction algorithms have recently become popular for minimizing the average of a large, but finite, number of loss functions. In this paper, we propose a novel Riemannian extension of the Euclidean stochastic variance…

Machine Learning · Computer Science 2017-04-11 Hiroyuki Kasai , Hiroyuki Sato , Bamdev Mishra

We consider optimization problems on manifolds with equality and inequality constraints. A large body of work treats constrained optimization in Euclidean spaces. In this work, we consider extensions of existing algorithms from the…

Optimization and Control · Mathematics 2019-04-26 Changshuo Liu , Nicolas Boumal

Industrial robots play a vital role in automatic production, which have been widely utilized in industrial production activities, like handling and welding. However, due to an uncalibrated robot with machining tolerance and assembly…

Robotics · Computer Science 2022-08-02 Zhibin Li , Shuai Li , Xin Luo

We report on a broader evaluation of statistical bootstrap resampling methods as a tool for pixel-level calibration and imaging fidelity assessment in radio interferometry. Pixel-level imaging fidelity assessment is a challenging problem,…

Instrumentation and Methods for Astrophysics · Physics 2015-05-14 Athol Kemball , Adam Martinsek , Modhurita Mitra , Hsin-Fang Chiang

We recently proposed the use of consensus optimization as a viable and effective way to improve the quality of calibration of radio interferometric data. We showed that it is possible to obtain far more accurate calibration solutions and…

Instrumentation and Methods for Astrophysics · Physics 2016-05-31 Sarod Yatawatta

Parameter-efficient fine-tuning methods such as LoRA enable practical adaptation of large language models but provide no principled uncertainty estimates, leading to poorly calibrated predictions and unreliable behavior under domain shift.…

Machine Learning · Computer Science 2026-02-23 Ibne Farabi Shihab , Sanjeda Akter , Anuj Sharma

The problem of recovering the configuration of points from their partial pairwise distances, referred to as the Euclidean Distance Matrix Completion (EDMC) problem, arises in a broad range of applications, including sensor network…

Optimization and Control · Mathematics 2026-05-07 Chandler Smith , HanQin Cai , Abiy Tasissa

Determining the ultimate limits of quantum communication, such as the quantum capacity of a channel and the distillable entanglement of a shared state, remains a central challenge in quantum information theory, primarily due to the…

Quantum Physics · Physics 2025-10-15 Chengkai Zhu , Hongyu Mao , Kun Fang , Xin Wang

We consider the minimization of a cost function $f$ on a manifold $M$ using Riemannian gradient descent and Riemannian trust regions (RTR). We focus on satisfying necessary optimality conditions within a tolerance $\varepsilon$.…

Optimization and Control · Mathematics 2018-05-01 Nicolas Boumal , P. -A. Absil , Coralia Cartis

Radio interferometers do not measure the sky brightness distribution directly but rather a modified Fourier transform of it. Imaging algorithms, thus, need a computational representation of the linear measurement operator and its adjoint,…

Instrumentation and Methods for Astrophysics · Physics 2021-02-10 Philipp Arras , Martin Reinecke , Rüdiger Westermann , Torsten A. Enßlin

To predict smooth physical phenomena from observations, spline interpolation provides an interpretable framework by minimizing an energy functional associated with the Laplacian operator. This work proposes a methodology to construct a…

Computation · Statistics 2026-03-26 Charlie Sire , Mike Pereira

There is growing interest in learning Fourier domain sampling strategies (particularly for magnetic resonance imaging, MRI) using optimization approaches. For non-Cartesian sampling patterns, the system models typically involve non-uniform…

Image and Video Processing · Electrical Eng. & Systems 2023-02-07 Guanhua Wang , Jeffrey A. Fessler

This manual is intended to help ALMA and other interferometer users improve images by recognising limitations and how to overcome them and deciding when and how to use self-calibration. The images provided by the ALMA Science Archive are…

Instrumentation and Methods for Astrophysics · Physics 2022-07-13 A. M. S. Richards , E. Moravec , S. Etoka , E. B. Fomalont , A. F. Pérez-Sánchez , M. C. Toribio , R. A. Laing

We consider a class of nonsmooth optimization problems over the Stiefel manifold, in which the objective function is weakly convex in the ambient Euclidean space. Such problems are ubiquitous in engineering applications but still largely…

Optimization and Control · Mathematics 2021-03-26 Xiao Li , Shixiang Chen , Zengde Deng , Qing Qu , Zhihui Zhu , Anthony Man Cho So

In this paper, we introduce some new iterative optimisation algorithms on Riemannian manifolds and Hilbert spaces which have good global convergence guarantees to local minima. More precisely, these algorithms have the following properties:…

Optimization and Control · Mathematics 2025-05-29 Tuyen Trung Truong

We present a new framework for statistical inference on Riemannian manifolds that achieves high-order accuracy, addressing the challenges posed by non-Euclidean parameter spaces frequently encountered in modern data science. Our approach…

Statistics Theory · Mathematics 2026-02-03 Chengzhu Huang , Anru R. Zhang