It is true that in all-optical networks, network performance can be improved by wavelength conversion. However, the switching node with wavelength conversion capability is still costly, and the number of such nodes sh...
详细信息
ISBN:
(纸本)0819426636
It is true that in all-optical networks, network performance can be improved by wavelength conversion. However, the switching node with wavelength conversion capability is still costly, and the number of such nodes should be limited in the network. In this paper, a performance optimization problem is treated in all-optical networks. We propose a heuristic algorithm to minimize an overall blocking probability by properly allocating a limited number of nodes with wavelength conversion capability. The routing streategy is also considered suitable to the case where the number of wavelength convertible nodes are limited. We validate the minimization level of our heuristic algorithm through numerical examples, and show that our algorithm can properly allocate nodes with conversion for performance optimizaition.
A Nash-Cournot model for oligopolistic markets with concave cost functions and a differentiated commodity is analyzed. Equilibrium states are characterized through Ky Fan inequalities. Relying on the minimization of a...
详细信息
A Nash-Cournot model for oligopolistic markets with concave cost functions and a differentiated commodity is analyzed. Equilibrium states are characterized through Ky Fan inequalities. Relying on the minimization of a suitable merit function, a general algorithmic scheme for solving them is provided. Two concrete algorithms are therefore designed that converge under suitable convexity and monotonicity assumptions. The results of some numerical tests on randomly generated markets are also reported.
Unplanned en-route charging of electric vehicles (EVs) can unexpectedly cripple traffic conditions. As lesseffective location of fast charging station (FCS) may exacerbate this issue, the effects of FCS on EVs' ch...
详细信息
Unplanned en-route charging of electric vehicles (EVs) can unexpectedly cripple traffic conditions. As lesseffective location of fast charging station (FCS) may exacerbate this issue, the effects of FCS on EVs' charging behaviors should be incorporated at the system planning stage. This paper proposes a strategic-chargingbehavior awared model in the context of electrified transportation network environment. This model is formulated into a bilevel mixed-integer programming problem. A newly designed network equilibrium model targets on the low-level problem, which is to model the drivers' charging reaction to a certain FCS layout. In considering the EV self-serving routing and charging behaviors as well as power network constraints, the upperlevel problem is formulated for location and sizing decision-makings, of which the objective is to minimize the overall traffic time and investment cost. To handle the proposed bilevel problem, a descent algorithm is further developed. To examine the effectiveness of the proposed approach, extensive numerical experiments are conducted, through which the obtained results demonstrate that the EV charging demand can perfectly be met while traffic congestions can be alleviated to a great extent.
In this paper, an optimal control problem for glass cooling processes is studied. We model glass cooling using the SP1 approximations to the radiative heat transfer equations. The control variable is the temperature a...
详细信息
In this paper, an optimal control problem for glass cooling processes is studied. We model glass cooling using the SP1 approximations to the radiative heat transfer equations. The control variable is the temperature at the boundary of the domain. This results in a boundary control problem for a parabolic/elliptic system which is treated by a constrained optimization approach. We consider several cost functionals of tracking-type and formally derive the first-order optimality system. Several numerical methods based on the adjoint variables are investigated. We present results of numerical simulations illustrating the feasibility and performance of the different approaches. Copyright (C) 2004 John Wiley Sons, Ltd.
In this paper, we are committed to the study of generalized difference gap (D-gap) functions and error bounds for hemivariational inequalities in Hilbert spaces. By introducing a new gap function, we define a generali...
详细信息
In this paper, we are committed to the study of generalized difference gap (D-gap) functions and error bounds for hemivariational inequalities in Hilbert spaces. By introducing a new gap function, we define a generalized D-gap function for the hemivariational inequality considered, for which we investigate the local Lipschitz continuity and coercivity. Then, some error bound results for the generalized D-gap function are established and the relationship between the solution to the hemivariational inequality and the stationary point of the generalized D-gap function is discussed. Finally, we construct a descent algorithm for solving the hemivariational inequality based on the generalized D-gap function and further prove a convergence result for the algorithm.
Wolfe’s convergence theory in optimisation is reformulated in the context of calculus of variations. Based on this reformulation , an algorithm with guaranteed finite termination and global convergence is proposed to...
详细信息
Wolfe’s convergence theory in optimisation is reformulated in the context of calculus of variations. Based on this reformulation , an algorithm with guaranteed finite termination and global convergence is proposed to solve calculus of variation problems. It is shown that the search direction found by this algorithm using the reformulated Wolfe's conditions is different from that found by solving the discretized version of the problem with Wolfe's conditions. It is a rgued that the reformulated Wolfe's conditions are more appropriat e for the discretized problem than the original ones. In an accompanying paper (A new algorithm to so lve calculus of variations problems using Wolfe’s co nvergence theory, Part II : Implementat-ion), a detailedimp lementation of the a lgorithm is present ed a nd numerical examples are given to illustrate the new algorithm
In this paper, a new inexact line search strategy is proposed, where a rough step length is firstly obtained by implementing the steps of backtracking in the Armijo line search, then it is improved by incorporating th...
详细信息
In this paper, a new inexact line search strategy is proposed, where a rough step length is firstly obtained by implementing the steps of backtracking in the Armijo line search, then it is improved by incorporating the features of the step length satisfying the approximate Wolfe condition. On the basis of the new line search, a modified Newton algorithm is developed to solve the unconstrained optimization problems. Under some suitable assumptions, the global convergence theory is established. Numerical experiments demonstrate that the new algorithm is effective, especially in comparison with the similar methods available in the literature.
In a companion paper (A new algorithm to solve calculus of variations problems using Wolfe's convergence theory, Part I: Theory and algorithm), a new algorithm with the properties of guaranteed finite termination ...
详细信息
In a companion paper (A new algorithm to solve calculus of variations problems using Wolfe's convergence theory, Part I: Theory and algorithm), a new algorithm with the properties of guaranteed finite termination and global convergence was proposed to solve calculus of variations problems. A detailed implementation of the algorithm is presented here. The implementation proposes a variable dimension method and incorporates a stable procedure to solve for the descent search direction. Numerical examples are given to illustrate the algorithm.
暂无评论