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Miller and Reif's FOCS'85 classic and fundamental tree contraction algorithm is a broadly applicable technique for the parallel solution of a large number of tree problems. Additionally it is also used as an algorithmic design technique for…

Data Structures and Algorithms · Computer Science 2021-11-04 MohammadTaghi Hajiaghayi , Marina Knittel , Hamed Saleh , Hsin-Hao Su

In tree based adaptive mesh refinement, elements are partitioned between processes using a space filling curve. The curve establishes an ordering between all elements that derive from the same root element, the tree. When representing more…

Distributed, Parallel, and Cluster Computing · Computer Science 2016-11-10 Carsten Burstedde , Johannes Holke

Automated analysis of optical coherence tomography (OCT) and OCT angiography (OCTA) images is critical for robust ophthalmic diagnosis. Existing mainstream methods trained from scratch rely heavily on massive data and model scale, thereby…

Computer Vision and Pattern Recognition · Computer Science 2026-04-07 Xiaofei Su , Zengshuo Wang , Minghe Sun , Xin Zhao , Mingzhu Sun

Developing a robust algorithm for automatic individual tree crown (ITC) detection from laser scanning datasets is important for tracking the responses of trees to anthropogenic change. Such approaches allow the size, growth and mortality of…

Computer Vision and Pattern Recognition · Computer Science 2019-10-04 Jonathan Williams , Carola-Bibiane Schönlieb , Tom Swinfield , Juheon Lee , Xiaohao Cai , Lan Qie , David A. Coomes

We study budget constrained network upgradeable problems. We are given an undirected edge weighted graph $G=(V,E)$ where the weight an edge $e \in E$ can be upgraded for a cost $c(e)$. Given a budget $B$ for improvement, the goal is to find…

Data Structures and Algorithms · Computer Science 2014-12-12 Debjyoti Saharoy , Sandeep Sen

This paper deals with the multiobjective version of the optimal spanning tree problem. More precisely, we are interested in determining the optimal spanning tree according to an Ordered Weighted Average (OWA) of its objective values. We…

Data Structures and Algorithms · Computer Science 2009-11-02 Lucie Galand , Olivier Spanjaard

Automated algorithm discovery in scientific computing faces fundamental challenges: vast design spaces with expensive evaluations, domain-specific physical constraints requiring expert knowledge, and the necessity for interpretable…

Artificial Intelligence · Computer Science 2025-11-18 He Wang , Liang Zeng

This paper presents a general framework for generating greedy algorithms for solving convex constraint satisfaction problems for sparse solutions by mapping the satisfaction problem into one of graph traversal on a rooted tree of unknown…

Data Structures and Algorithms · Computer Science 2015-09-16 Tarek A. Lahlou , Alan V. Oppenheim

Although GRPO substantially enhances flow matching models in human preference alignment of image generation, methods such as FlowGRPO and DanceGRPO still exhibit inefficiency due to the necessity of sampling and optimizing over all…

Artificial Intelligence · Computer Science 2026-03-23 Junzhe Li , Yutao Cui , Tao Huang , Yinping Ma , Chun Fan , Yiming Cheng , Miles Yang , Zhao Zhong , Liefeng Bo

Estimating per-pixel motion between video frames, known as optical flow, is a long-standing problem in video understanding and analysis. Most contemporary optical flow techniques largely focus on addressing the cross-image matching with…

Computer Vision and Pattern Recognition · Computer Science 2022-02-09 Ao Luo , Fan Yang , Kunming Luo , Xin Li , Haoqiang Fan , Shuaicheng Liu

We present an algorithm to solve the dispersive depth-averaged Serre-Green-Naghdi (SGN) equations using patch-based adaptive mesh refinement. These equations require adding additional higher derivative terms to the nonlinear shallow water…

Numerical Analysis · Mathematics 2024-09-04 Marsha J. Berger , Randall J. LeVeque

We consider the problem of compactly representing the Depth First Search (DFS) tree of a given undirected or directed graph having $n$ vertices and $m$ edges while supporting various DFS related queries efficiently in the RAM with…

Data Structures and Algorithms · Computer Science 2019-06-20 Sankardeep Chakraborty , Kunihiko Sadakane

This paper presents an adaptive amoeba algorithm to address the shortest path tree (SPT) problem in dynamic graphs. In dynamic graphs, the edge weight updates consists of three categories: edge weight increases, edge weight decreases, the…

Neural and Evolutionary Computing · Computer Science 2013-11-05 Xiaoge Zhang , Qi Liu , Yong Hu , Felix T. S. Chan , Sankaran Mahadevan , Zili Zhang , Yong Deng

In this thesis, we develop, discuss and implement algorithms for scalable parallel tree-based adaptive mesh refinement (AMR) using space-filling curves (SFCs). We create an AMR software that works independently of the used element type,…

Distributed, Parallel, and Cluster Computing · Computer Science 2019-10-22 Johannes Holke

We propose a mesh adaptation procedure for Cartesian quadtree meshes, to discretize scalar advection-diffusion-reaction problems. The adaptation process is driven by a recovery-based a posteriori estimator for the $L^2(\Omega)$-norm of the…

Numerical Analysis · Mathematics 2022-12-13 Pasquale Claudio Africa , Simona Perotto , Carlo de Falco

The performance of large language models (LLMs) across diverse downstream applications is fundamentally governed by the quality and composition of their pretraining corpora. Existing domain reweighting algorithms primarily optimize data…

Machine Learning · Computer Science 2025-05-28 Simin Fan , Maria Ios Glarou , Martin Jaggi

We present the first known pivot Gray code for spanning trees of complete graphs, listing all spanning trees such that consecutive trees differ by pivoting a single edge around a vertex. This pivot Gray code thus addresses an open problem…

Data Structures and Algorithms · Computer Science 2025-10-28 Bowie Liu , Dennis Wong , Chan-Tong Lam , Sio-Kei Im

Considering the worst-case scenario, junction tree algorithm remains the most general solution for exact MAP inference with polynomial run-time guarantees. Unfortunately, its main tractability assumption requires the treewidth of a…

Discrete Mathematics · Computer Science 2022-02-10 Alexander Bauer , Shinichi Nakajima

The TREE method has been widely used for long-range interaction {\it N}-body problems. We have developed a parallel TREE code for two-component classical plasmas with open boundary conditions and highly non-uniform charge distributions. The…

Computational Physics · Physics 2009-05-04 Byoungseon Jeon , Joel D. Kress , Lee A. Collins , Niels Grønbech-Jensen

Accurate polyp segmentation remains challenging due to irregular lesion morphologies, ambiguous boundaries, and heterogeneous imaging conditions. While U-Net variants excel at local feature fusion, they often lack explicit mechanisms to…

Image and Video Processing · Electrical Eng. & Systems 2025-02-27 Pu Wang , Huaizhi Ma , Zhihua Zhang , Zhuoran Zheng