In this paper, some simple and practical multilevel preconditioners for Hermite conforming and some well known nonconforming finite elements are constructed.
In this paper, we consider some multigrid algorithms for the biharmonic problem discretized by Morley element on nonnested meshes. Through taking the averages of the nodal variables we construct an intergrid transfer ...In this paper, we consider some multigrid algorithms for the biharmonic problem discretized by Morley element on nonnested meshes. Through taking the averages of the nodal variables we construct an intergrid transfer operator that satisfies a certain stable approximation property. The so-called regularity-approximation assumption is then established. Optimal convergence properties of the W-cycle and a uniform condition number estimate for the variable V-cycle preconditioner are presented. This technique is applicable to other nonconforming plate elements.展开更多
This paper provides a proof for the uniform convergence rate （independently of the number of mesh levels） for the nonnested V-cycle multigrid method for nonsymmetric and indefinite second-order elliptic problems.
This paper studies airlines＇ competitive behavior in the U.S. airline in- dustry, focusing on 2014 data. I use a structural model to estimate demand and test several supply models, including noncooperative competitio...This paper studies airlines＇ competitive behavior in the U.S. airline in- dustry, focusing on 2014 data. I use a structural model to estimate demand and test several supply models, including noncooperative competition, perfect collusion, and tacit coordination. There are three different types of tacit coordination, formed by multimarket contact, common ownership, and codeshare agreement, respectively. I find that the model that fits the data best is a tacit coordination model with coalitions between airlines with at least 30% of their markets overlapped and using price rather than quantity as the strategic variable. I further analyze the consumer welfare loss, each carrier＇s profit gains, and changes in market variables due to the tacit coordination.展开更多
文摘In this paper, some simple and practical multilevel preconditioners for Hermite conforming and some well known nonconforming finite elements are constructed.
文摘In this paper, we consider some multigrid algorithms for the biharmonic problem discretized by Morley element on nonnested meshes. Through taking the averages of the nodal variables we construct an intergrid transfer operator that satisfies a certain stable approximation property. The so-called regularity-approximation assumption is then established. Optimal convergence properties of the W-cycle and a uniform condition number estimate for the variable V-cycle preconditioner are presented. This technique is applicable to other nonconforming plate elements.
文摘This paper provides a proof for the uniform convergence rate （independently of the number of mesh levels） for the nonnested V-cycle multigrid method for nonsymmetric and indefinite second-order elliptic problems.
文摘This paper studies airlines＇ competitive behavior in the U.S. airline in- dustry, focusing on 2014 data. I use a structural model to estimate demand and test several supply models, including noncooperative competition, perfect collusion, and tacit coordination. There are three different types of tacit coordination, formed by multimarket contact, common ownership, and codeshare agreement, respectively. I find that the model that fits the data best is a tacit coordination model with coalitions between airlines with at least 30% of their markets overlapped and using price rather than quantity as the strategic variable. I further analyze the consumer welfare loss, each carrier＇s profit gains, and changes in market variables due to the tacit coordination.
