A High-Order / Low-Order (HOLO) Algorithm with Low-Rank Evolution for Time-Dependent Transport Calculations

2019 ◽  
Author(s):  
R. McClarren ◽  
Z. Peng
Mathematics ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 1113
Author(s):  
Isaías Alonso-Mallo ◽  
Ana M. Portillo

The initial boundary-value problem associated to a semilinear wave equation with time-dependent boundary values was approximated by using the method of lines. Time integration is achieved by means of an explicit time method obtained from an arbitrarily high-order splitting scheme. We propose a technique to incorporate the boundary values that is more accurate than the one obtained in the standard way, which is clearly seen in the numerical experiments. We prove the consistency and convergence, with the same order of the splitting method, of the full discretization carried out with this technique. Although we performed mathematical analysis under the hypothesis that the source term was Lipschitz-continuous, numerical experiments show that this technique works in more general cases.


Author(s):  
Giacomo Albi ◽  
Lorenzo Pareschi

AbstractWe consider the construction of semi-implicit linear multistep methods that can be applied to time-dependent PDEs where the separation of scales in additive form, typically used in implicit-explicit (IMEX) methods, is not possible. As shown in Boscarino et al. (J. Sci. Comput. 68: 975–1001, 2016) for Runge-Kutta methods, these semi-implicit techniques give a great flexibility, and allow, in many cases, the construction of simple linearly implicit schemes with no need of iterative solvers. In this work, we develop a general setting for the construction of high order semi-implicit linear multistep methods and analyze their stability properties for a prototype linear advection-diffusion equation and in the setting of strong stability preserving (SSP) methods. Our findings are demonstrated on several examples, including nonlinear reaction-diffusion and convection-diffusion problems.


2012 ◽  
Vol 61 (2-3) ◽  
pp. 305-316 ◽  
Author(s):  
V. Gudmundsson ◽  
O. Jonasson ◽  
Th. Arnold ◽  
C-S. Tang ◽  
H.-S. Goan ◽  
...  

2011 ◽  
Vol 308-310 ◽  
pp. 2560-2564 ◽  
Author(s):  
Xiang Rong Yuan

A moving fitting method for edge detection is proposed in this work. Polynomial function is used for the curve fitting of the column of pixels near the edge. Proposed method is compared with polynomial fitting method without sub-segment. The comparison shows that even with low order polynomial, the effects of moving fitting are significantly better than that with high order polynomial fitting without sub-segment.


2021 ◽  
Vol 30 (06) ◽  
Author(s):  
Wenjin Qin ◽  
Hailin Wang ◽  
Feng Zhang ◽  
Mingwei Dai ◽  
Jianjun Wang
Keyword(s):  
Low Rank ◽  

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