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Coordinate-based neural networks parameterizing implicit surfaces have emerged as efficient representations of geometry. They effectively act as parametric level sets with the zero-level set defining the surface of interest. We present a…

Computer Vision and Pattern Recognition · Computer Science 2022-07-22 Ishit Mehta , Manmohan Chandraker , Ravi Ramamoorthi

An inverse problem of identifying inhomogeneity or crack in the workpiece made of nonlinear magnetic material is investigated. To recover the shape from the local measurements, a piecewise constant level set algorithm is proposed. By means…

Mathematical Physics · Physics 2012-12-04 Xiangyin Kong , Zhengfang Zhang , Zhengda Huang

Random media introduce large degrees of freedom in device design and can thus address challenges in manipulating optical waves. Wave shaping with metasurfaces has mainly utilized periodic or quasi-periodic grids, and, the potential of…

Optics · Physics 2018-08-28 Hadiseh Nasari , Matthieu Dupré , Boubacar Kanté

We present a computational framework for efficient optimization-based "inverse design" of large-area "metasurfaces" (subwavelength-patterned surfaces) for applications such as multi-wavelength and multi-angle optimizations, and…

The level set approach represents surfaces implicitly, and advects them by evolving a level set function, which is numerically defined on an Eulerian grid. Here we present an approach that augments the level set function values by gradient…

Numerical Analysis · Mathematics 2015-05-13 Jean-Christophe Nave , Rodolfo Ruben Rosales , Benjamin Seibold

Level set method has been used to capture interface motion. Narrow band algorithm is applied to localize the solving of level-set PDE on global domain to a tube around interface. Due to the unknown evolving interface, narrow band algorithm…

Computational Physics · Physics 2016-12-14 Zhenlin Wang

Obtaining high quality particle distribution representing clean geometry in pre-processing is essential for the simulation accuracy of the particle-based methods. In this paper, several level-set based techniques for cleaning up `dirty'…

Computational Engineering, Finance, and Science · Computer Science 2023-05-01 Yongchuan Yu , Yujie Zhu , Chi Zhang , Oskar J. Haidn , Xiangyu Hu

This work presents a rigorous mathematical formulation for topology optimization of a macrostructure undergoing ductile failure. The prediction of ductile solid materials which exhibit dominant plastic deformation is an intriguingly…

Numerical Analysis · Mathematics 2023-03-22 Nima Noii , Hassan Ali Jahangiry , Haim Waisman

Since the seminal work of Idelsohn, O\~nate and Del-Pin (2004), the Particle Finite Element Method (PFEM) has relied on a Delaunay triangulation and the Alpha--Shape (AS) algorithm in the remeshing process. This approach guarantees a good…

Electromagnetic metasurface design based on far-field constraints without the complete knowledge of the fields on both sides of the metasurface is typically a time consuming and iterative process, which relies heavily on heuristics and ad…

Optics · Physics 2022-08-17 Parinaz Naseri , Stewart Pearson , Zhengzheng Wang , Sean V. Hum

In this paper, we study triply periodic surfaces with minimal surface area under a constraint in the volume fraction of the regions (phases) that the surface separates. Using a variational level set method formulation, we present a…

Optimization and Control · Mathematics 2015-06-26 Youngjean Jung , Kevin T. Chu , Salvatore Torquato

Level set-based immersed boundary techniques operate on nonconforming meshes while providing a crisp definition of interface and external boundaries. In such techniques, an isocontour of a level set field interpolated from nodal level set…

Computational Engineering, Finance, and Science · Computer Science 2020-07-15 Jorge L. Barrera , Kurt Maute

In this paper, we propose a low-rank coordinate descent approach to structured semidefinite programming with diagonal constraints. The approach, which we call the Mixing method, is extremely simple to implement, has no free parameters, and…

Optimization and Control · Mathematics 2026-05-12 Po-Wei Wang , Wei-Cheng Chang , J. Zico Kolter

The classical level set method, which represents the boundary of the unknown geometry as the zero-level set of a function, has been shown to be very effective in solving shape optimization problems. The present work addresses the issue of…

Optimization and Control · Mathematics 2025-10-20 Oleg Alexandrov , Fadil Santosa

A new concept for the higher-order accurate approximation of partial differential equations on manifolds is proposed where a surface mesh composed by higher-order elements is automatically generated based on level-set data. Thereby, it…

Numerical Analysis · Computer Science 2017-10-11 T. P. Fries , D. Schöllhammer

Subsampling of node sets is useful in contexts such as multilevel methods, computer graphics, and machine learning. On uniform grid-based node sets, the process of subsampling is simple. However, on node sets with high density variation,…

Numerical Analysis · Mathematics 2023-05-19 Andrew P. Lawrence , Morten E. Nielsen , Bengt Fornberg

We propose a numerical method for solving block-structured mesh partitioning problems based on the variational level-set method of (Zhao et al., J Comput Phys 127, 1996) which has been widely used in many partitioning problems such as image…

Computational Physics · Physics 2018-01-12 Shucheng Pan , Xiangyu Hu , Nikolaus. A. Adams

In this paper we present approaches that address two issues that can occur when the level-set method is used to simulate two-fluid flows in engineering practice. The first issue concerns regularizing the Heaviside function on arbitrary…

Numerical Analysis · Mathematics 2018-02-02 Ido Akkerman

Metasurfaces are generally designed by placing scatterers in periodic or pseudo-periodic grids. We propose and discuss design rules for functional metasurfaces with randomly placed anisotropic elements. By analyzing the focusing performance…

Optics · Physics 2018-02-06 Matthieu Dupré , Liyi Hsu , Boubacar Kanté

Metasurfaces are an emerging technology that may supplant many of the conventional optics found in imaging devices, displays, and precision scientific instruments. Here, we develop a method for designing optical systems composed of multiple…

Optics · Physics 2019-10-23 Adam S. Backer