paper-with-me

홈 › Papers

Sparse Signal Reconstruction for Nonlinear Models via Piecewise Rational Optimization

2020-10-29 · Arthur Marmin, Marc Castella, Jean-Christophe Pesquet, Laurent Duval

We propose a method to reconstruct sparse signals degraded by a nonlinear distortion and acquired at a limited sampling rate. Our method formulates the reconstruction problem as a nonconvex minimization of the sum of a data fitting term and a penalization term. In contrast with most previous works which settle for approximated local solutions, we seek for a global solution to the obtained challenging nonconvex problem. Our global approach relies on the so-called Lasserre relaxation of polynomial optimization. We here specifically include in our approach the case of piecewise rational functions, which makes it possible to address a wide class of nonconvex exact and continuous relaxations of the $\ell_0$ penalization function. Additionally, we study the complexity of the optimization problem. It is shown how to use the structure of the problem to lighten the computational burden efficiently. Finally, numerical simulations illustrate the benefits of our method in terms of both global optimality and signal reconstruction.

📄 PDF Abstract BibTeX arXiv:2010.15427

Code (0)

등록된 구현이 없습니다.

Similar Papers 제목 키워드 기반

Rational Optimization for Nonlinear Reconstruction with Approximate $\ell_0$ Penalization

2018-12-21

Recovering nonlinearly degraded signal in the presence of noise is a challenging problem. In this work, this problem is tackled by minimizing the sum of a non convex least-squares fit criterion and a penalty term. We ass…

Piecewise Flat Embedding for Image Segmentation

2018-02-09 · ICCV 2015 12 · Chaowei Fang, Zicheng Liao, Yizhou Yu

We introduce a new multi-dimensional nonlinear embedding -- Piecewise Flat Embedding (PFE) -- for image segmentation. Based on the theory of sparse signal recovery, piecewise flat embedding with diverse channels attempts…

ClusteringContour DetectionImage SegmentationSegmentation+1

Parametric Level-sets Enhanced To Improve Reconstruction (PaLEnTIR)

2022-04-21 · Ege Ozsar, Misha Kilmer, Eric Miller, Eric de Sturler 외

We introduce PaLEnTIR, a significantly enhanced parametric level-set (PaLS) method addressing the restoration and reconstruction of piecewise constant objects. Our key contribution involves a unique PaLS formulation util…

Denoising

Perfect reconstruction of sparse signals with piecewise continuous nonconvex penalties and nonconvexity control

2019-02-20 · Ayaka Sakata, Tomoyuki Obuchi

We consider compressed sensing formulated as a minimization problem of nonconvex sparse penalties, Smoothly Clipped Absolute deviation (SCAD) and Minimax Concave Penalty (MCP). The nonconvexity of these penalties is cont…

compressed sensing

Rational Sparse Autoencoder

2026-06-12 · Naiyu Yin, Yue Yu arxiv

Sparse autoencoders (SAEs) are standard tools for mechanistic interpretability, but current SAE families are constrained by fixed encoder nonlinearities such as ReLU, JumpReLU, and TopK. This hard-codes a particular spar…