The finite element scheme is proposed and analyzed for the solution of an acid-mediated tumor invasion model. The reaction-diffusion equation shows the evolution in the tumor cell density, H + ions concentration, and ...
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The finite element scheme is proposed and analyzed for the solution of an acid-mediated tumor invasion model. The reaction-diffusion equation shows the evolution in the tumor cell density, H + ions concentration, and healthy tissue density over time. The coupled non-linear partial differential equations are discretized in time with the implicit Euler method and in space with standard Galerkin finite element. To solve the non-linear and coupled terms of the system a fixed point iteration scheme is presented. Moreover, a mass-lumped scheme is adopted to reduce the computation cost. The cut-off method is used to compute the bounded solutions of the PDEs. Finally, The effects of proliferation rate and healthy tissue degradation rate are investigated.
The dynamic fracture of quasi-brittle heterogeneous materials is governed by processes at several different scale levels. Each of these processes is either independent or dependent on the others. In order to model the...
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The dynamic fracture of quasi-brittle heterogeneous materials is governed by processes at several different scale levels. Each of these processes is either independent or dependent on the others. In order to model the dynamic fracture of such materials, it is necessary to account for all the rupture processes that contribute to the overall fracture process. This paper presents a structural-temporal approach for the analysis of the multi-scale nature of dynamic fracture based on the notion of a spatial-temporal fracture cell for different scale levels. The problem of the experimental determination of fracture parameters at a given scale level and their possible interconnections with higher and lower scale levels are discussed. It is shown that these interconnections can permit the prediction of fracture parameters on a higher (real) scale level based on the test data obtained on a lower (laboratory) scale. This predictive capability is of vital importance in many applications in which it is not possible to evaluate the dynamic material properties on the real structural scale level (e.g. geological formations, large concrete structures, trunk pipelines, etc.). (C) 2012 Elsevier Ltd. All rights reserved.
Connected vehicle (CV) technology has great potential to improve the performance of today's advanced driver assistance systems in terms of safety, energy efficiency, and driving comfort. The aim of this paper is t...
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Connected vehicle (CV) technology has great potential to improve the performance of today's advanced driver assistance systems in terms of safety, energy efficiency, and driving comfort. The aim of this paper is to develop a specific CV application that assists with lane selection, i.e., finding the best travel lane in terms of travel time based on predicted lane-level traffic states. In this paper, a spatial-temporal model (ST-model) was developed, which utilizes spatial and temporal information of road cells to predict future traffic states. This information was used by the proposed lane selection assistance application to select an optimal lane sequence for the application-equipped vehicle. A comprehensive simulation-based evaluation was then conducted under various scenarios, e.g., with different traffic volumes, penetration rates of communication-capable vehicles, and information update cycles. The evaluation results reveal several interesting findings, including: 1) the proposed ST-model outperforms the basic estimation model in terms of traffic state prediction accuracy;2) travel times of application-equipped vehicles can be reduced by up to 8% with the use of the proposed lane selection assistance application when compared with the baseline, under various traffic scenarios;3) the application can be effective in the early deployment stage of CV technology, where the penetration rate of communication-capable vehicles is still low;and 4) the potential conflict risk of application-equipped vehicles is reduced, although the application is mainly designed for mobility benefits, due to the more strategic and informed lane changes suggested by the proposed application.
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