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Related papers: Geometric Firefighting in the Half-plane

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Various flame tracking techniques are often used in hydrodynamic simulations. Their use is indispensable when resolving actual scale of the flame is impossible. We show that parameters defining "artificial flame" propagation found from…

Astrophysics · Physics 2007-05-23 Andrey V. Zhiglo

Early detection of wildfires is essential to prevent large-scale fires resulting in extensive environmental, structural, and societal damage. Uncrewed aerial vehicles (UAVs) can cover large remote areas effectively with quick deployment…

Computer Vision and Pattern Recognition · Computer Science 2024-12-19 Julius Pesonen , Teemu Hakala , Väinö Karjalainen , Niko Koivumäki , Lauri Markelin , Anna-Maria Raita-Hakola , Juha Suomalainen , Ilkka Pölönen , Eija Honkavaara

Different one-phase Stefan problems for a semi-infinite slab are considered, involving a moving phase change material as well as temperature dependent thermal coefficients. Existence of at least one similarity solution is proved imposing a…

Analysis of PDEs · Mathematics 2021-05-12 Julieta Bollati , Adriana C. Briozzo

We build in this paper a numerical solution procedure to compute the flow induced by a spherical flame expanding from a point source at a constant expansion velocity, with an instantaneous chemical reaction. The solution is supposed to be…

Numerical Analysis · Mathematics 2020-10-19 D Grapsas , R Herbin , J. -C Latché , Y Nasseri

The problem of front propagation in a stirred medium is addressed in the case of cellular flows in three different regimes: slow reaction, fast reaction and geometrical optics limit. It is well known that a consequence of stirring is the…

Chaotic Dynamics · Physics 2009-11-07 M. Abel , M. Cencini , D. Vergni , A. Vulpiani

We study the fundamental problem of two gas species in two dimensional velocity space whose molecules collide as hard circles in the presence of a flat boundary and with dependence on only one space dimension. The case of three-dimensional…

Analysis of PDEs · Mathematics 2009-11-11 A. Sotirov

This paper concerns compressible subsonic jet flows for a given surrounding pressure from a two-dimensional finitely long convergent nozzle with straight solid wall, which are governed by a free boundary problem for a quasilinear elliptic…

Analysis of PDEs · Mathematics 2019-02-08 Chunpeng Wang , Zhouping Xin

We prove that at least $\Omega(n^{0.51})$ hyperplanes are needed to slice all edges of the $n$-dimensional hypercube. We provide a couple of applications: lower bounds on the computational complexity of parity, and a lower bound on the…

Combinatorics · Mathematics 2021-02-18 Gal Yehuda , Amir Yehudayoff

Wildfires are destructive and inflict massive, irreversible harm to victims' lives and natural resources. Researchers have proposed commissioning unmanned aerial vehicles (UAVs) to provide firefighters with real-time tracking information;…

Robotics · Computer Science 2019-03-19 Esmaeil Seraj , Andrew Silva , Matthew Gombolay

We consider the initial value problem for the thermal-diffusive combustion systems of the form: $u_{1,t}= Delta_{x}u_1 - u_1 u_2^m$, $u_{2,t}= d Delta_{x} u_2 + u_1 u_2^m$, $x in R^{n}$, $n geq 1$, $m geq 1$, $d > 1$, with bounded uniformly…

chao-dyn · Physics 2016-08-31 P. Collet , J. Xin

A geometric model for the computation of the firefront of a forest wildfire which takes into account several effects (possibly time-dependent wind, anisotropies and slope of the ground) is introduced. It relies on a general theoretical…

Differential Geometry · Mathematics 2024-08-07 Miguel Ángel Javaloyes , Enrique Pendás-Recondo , Miguel Sánchez

Extending results of Hershberger and Suri for the Euclidean plane, we show that ball hulls and ball intersections of sets of $n$ points in strictly convex normed planes can be constructed in $O(n \log n)$ time. In addition, we confirm that,…

Metric Geometry · Mathematics 2014-11-28 Pedro Martín , Horst Martini

We propose a method to reconstruct dynamic fire in 3D from a limited set of camera views with a Gaussian-based spatiotemporal representation. Capturing and reconstructing fire and its dynamics is highly challenging due to its volatile…

Computer Vision and Pattern Recognition · Computer Science 2025-12-01 Jakob Nazarenus , Dominik Michels , Wojtek Palubicki , Simin Kou , Fang-Lue Zhang , Soren Pirk , Reinhard Koch

In this work, we carry out structural and algorithmic studies of a problem of barrier forming: selecting theminimum number of straight line segments (barriers) that separate several sets of mutually disjoint objects in the plane. The…

Robotics · Computer Science 2022-02-25 Si Wei Feng , Jingjin Yu

Recently it was obtained in [Tarzia, Thermal Sci. 21A (2017) 1-11] for the classical two-phase Lam\'e-Clapeyron-Stefan problem an equivalence between the temperature and convective boundary conditions at the fixed face under a certain…

Mathematical Physics · Physics 2018-10-17 Julieta Bollati , Domingo A. Tarzia

This paper estimates the blow-up time for the heat equation $u_t=\Delta u$ with a local nonlinear Neumann boundary condition: The normal derivative $\partial u/\partial n=u^{q}$ on $\Gamma_{1}$, one piece of the boundary, while on the rest…

Analysis of PDEs · Mathematics 2016-06-08 Xin Yang , Zhengfang Zhou

In this paper, we discuss existence and finite speed of propagation for the solutions to an initial-boundary value problem for a family of fractional thin-film equations in a bounded domain in $\mathbb{R}^d$. The nonlocal operator we…

Analysis of PDEs · Mathematics 2025-05-20 Nicola De Nitti , Stefano Lisini , Antonio Segatti , Roman Taranets

Using a new general approach to limits in optical structures that counts orthogonal waves generated by scattering, we derive an upper limit to the number of bits of delay possible in one-dimensional slow light structures that are based on…

Optics · Physics 2013-02-08 David A. B. Miller

A reaction-diffusion model which is called the field-road model was introduced by Berestycki, Roquejoffre and Rossi [9] to describe biological invasion with fast diffusion on a line. In this paper, we investigate this model in a…

Analysis of PDEs · Mathematics 2022-05-12 Mingmin Zhang

We study the speed of propagation of fronts for the scalar reaction-diffusion equation $u_t = u_{xx} + f(u)$\, with $f(0) = f(1) = 0$. We give a new integral variational principle for the speed of the fronts joining the state $u=1$ to…

patt-sol · Physics 2009-10-28 R. D. Benguria , M. C. Depassier
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