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Related papers: Hierarchical octree and k-d tree grids for 3D radi…

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Interactions between clouds and radiation are at the root of many difficulties in numerically predicting future weather and climate and in retrieving the state of the atmosphere from remote sensing observations. The large range of issues…

We present mock optical images, broad-band and H$\alpha$ fluxes, and D4000 spectral indices for 30,145 galaxies from the EAGLE hydrodynamical simulation at redshift $z=0.1$, modelling dust with the SKIRT Monte Carlo radiative transfer code.…

DBSCAN is a fundamental spatial clustering algorithm with numerous practical applications. However, a bottleneck of the algorithm is in the worst case, the run time complexity is $O(n^2)$. To address this limitation, we propose a new…

Databases · Computer Science 2022-11-08 Xiaogang Huang , Tiefeng Ma , Conan Liu , Shuangzhe Liu

The $K$-core of a graph is the unique maximum subgraph within which each vertex connects to $K$ or more other vertices. The optimal $K$-core attack problem asks to delete the minimum number of vertices from the $K$-core to induce its…

Disordered Systems and Neural Networks · Physics 2024-06-17 Jianwen Zhou , Hai-Jun Zhou

The automated finite element analysis of complex CAD models using boundary-fitted meshes is rife with difficulties. Immersed finite element methods are intrinsically more robust but usually less accurate. In this work, we introduce an…

Numerical Analysis · Mathematics 2026-01-28 Eky Febrianto , Jakub Sistek , Pavel Kus , Matija Kecman , Fehmi Cirak

We discuss the efficiency of Monte Carlo methods in solving continuum radiative transfer problems. The sampling of the radiation field and convergence of dust temperature calculations in the case of optically thick clouds are both studied.…

Astrophysics · Physics 2009-11-10 M. Juvela

A method is presented to include irregular domain boundaries in a geometric multigrid solver. Dirichlet boundary conditions can be imposed on an irregular boundary defined by a level set function. Our implementation employs quadtree/octree…

Numerical Analysis · Mathematics 2023-01-26 Jannis Teunissen , Francesca Schiavello

Owing to the recent, rapid development of computer technology, the resolution of atmospheric numerical models has increased substantially. With the use of next-generation supercomputers, atmospheric simulations using horizontal grid…

Numerical Analysis · Mathematics 2016-05-25 H. Yamazaki , T. Satomura , N. Nikiforakis

The convergence rate of a multigrid method depends on the properties of the smoother and the so-called grid transfer operator. In this paper we define and analyze new grid transfer operators with a generic cutting size which are applicable…

Numerical Analysis · Mathematics 2016-08-12 Maria Charina , Marco Donatelli , Lucia Romani , Valentina Turati

This paper introduces the notion of distributed verification without preprocessing. It focuses on the Minimum-weight Spanning Tree (MST) verification problem and establishes tight upper and lower bounds for the time and message complexities…

Distributed, Parallel, and Cluster Computing · Computer Science 2015-12-16 Liah Kor , Amos Korman , David Peleg

Grid graphs, and, more generally, $k\times r$ grid graphs, form one of the most basic classes of geometric graphs. Over the past few decades, a large body of works studied the (in)tractability of various computational problems on grid…

Data Structures and Algorithms · Computer Science 2021-07-01 Siddharth Gupta , Guy Sa'ar , Meirav Zehavi

3D non-LTE radiative transfer problems are computationally demanding, and this sets limits on the size of the problems that can be solved. So far Multilevel Accelerated Lambda Iteration (MALI) has been to the method of choice to perform…

Solar and Stellar Astrophysics · Physics 2017-03-15 Johan P. Bjørgen , Jorrit Leenaarts

A key challenge for LiDAR-based 3D object detection is to capture sufficient features from large scale 3D scenes especially for distant or/and occluded objects. Albeit recent efforts made by Transformers with the long sequence modeling…

Computer Vision and Pattern Recognition · Computer Science 2023-03-23 Chao Zhou , Yanan Zhang , Jiaxin Chen , Di Huang

The study of optimal decision trees has gained increasing attention in recent years; however, despite substantial progress, it still suffers from two major challenges: First, trees constructed by existing optimal decision tree (ODT)…

Machine Learning · Computer Science 2026-05-04 Xi He

For numerical simulations of cosmic-ray propagation fast access to static magnetic field data is required. We present a data structure for multiresolution vector grids which is optimized for fast access, low overhead and shared memory use.…

Instrumentation and Methods for Astrophysics · Physics 2016-08-23 Gero Müller

We revisit the generation of balanced octrees for adaptive mesh refinement (AMR) of Cartesian domains with immersed complex geometries. In a recent short note [Hasbestan and Senocak, J. Comput. Phys. vol. 351:473-477 (2017)], we showed that…

Computational Engineering, Finance, and Science · Computer Science 2018-05-23 Jaber J. Hasbestan , Inanc Senocak

Previously in 2014, we proposed the Nearest Descent (ND) method, capable of generating an efficient Graph, called the in-tree (IT). Due to some beautiful and effective features, this IT structure proves well suited for data clustering.…

Machine Learning · Statistics 2016-03-07 Teng Qiu , Yongjie Li

3D content generation remains a fundamental yet challenging task due to the inherent structural complexity of 3D data. While recent octree-based diffusion models offer a promising balance between efficiency and quality through hierarchical…

Computer Vision and Pattern Recognition · Computer Science 2025-08-18 Xinjie Gao , Bi'an Du , Wei Hu

The number of the non-shared edges of two phylogenies is a basic measure of the dissimilarity between the phylogenies. The non-shared edges are also the building block for approximating a more sophisticated metric called the nearest…

Data Structures and Algorithms · Computer Science 2007-05-23 Wing-Kai Hon , Ming-Yang Kao , Tak-Wah Lam , Wing-Kin Sung , Siu-Ming Yiu

We have developed a 3-D Monte Carlo radiative transfer model which computes line and continuum polarization variability for a binary system with an optically thick non-axisymmetric envelope. This allows us to investigate the complex…

Astrophysics · Physics 2009-11-07 R. Kurosawa , D. J. Hillier