This work develops a bi-level optimization model for locating bus stops to minimize the social cost of the overall transport system. The work takes into account possible changes in demand due to different bus stop loc...
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This work develops a bi-level optimization model for locating bus stops to minimize the social cost of the overall transport system. The work takes into account possible changes in demand due to different bus stop locations considering congestion on buses, interaction with private traffic, operational variables (fleet, frequency, operator budgets), and the socio-demographic characteristics of each zone in the urban area. Finally, the technique is applied to a real case and a sensitivity analysis is performed to check how the different variables analysed influence the solution provided by the model. (C) 2009 Elsevier Ltd. All rights reserved.
The concepts of transport mode energy consumption and road network capacity are explained in the paper, which are applied to forecast the minimum energy consumption in a Meg polis. A bi-level optimization model is use...
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ISBN:
(纸本)9781424448135
The concepts of transport mode energy consumption and road network capacity are explained in the paper, which are applied to forecast the minimum energy consumption in a Meg polis. A bi-level optimization model is used, where upper-level establishes energy consumption consistent with the maximum road network capacity, while the lower level assigns traffic demand across the network. Modal split and the capacity models of vehicle roads are used to connect the two levels. The idea and method can be applied to the process of urban traffic planning so as to promote the sustainable development of urban transportation and environment. When traffic demand is more than traffic supply, transport structure can be adjusted according to the value of energy consumption by traffic modes.
In order to determine the maximum internal forces acting on certain joint of a walking mechanism for the structural strength analysis, a mechanical model for the chassis including all position freedom parameters o...
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In order to determine the maximum internal forces acting on certain joint of a walking mechanism for the structural strength analysis, a mechanical model for the chassis including all position freedom parameters of the mechanism in operation is established, and an optimizationmodel for determining the internal force of the walking mechanism is presented as well. A method using the bi-level optimization model based on multilayer perceptron (MLP) for solving the optimization problem is proposed. In the first level, the maximum forces acting on certain joint of the chassis are optimized by the sequential quadratic programming method at a set of positional parameters. The MLP, as a nonlinear mapping relationship between the maximum force state at certain joint and the positional parameters, is trained by using orthogonal design. In the second level, the genetic algorithm is used to optimize the MLP. A high precision MLP is obtained through an iterative procedure, in which the searching volume is reduced by using the bisection method. The results indicate that the proposed method is effective in solving the multivariable optimization of the complex structural system. It is also concluded that the method provides a theoretical basis for designing the walking mechanism.
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