An augmented lagrangean dual algorithm for link capacity side constrained traffic assignment problems

An Augmented Lagrangean Dual Algorithm for Link Capacity Side Constrained Traac Assignment Problems

As a means to obtain a more accurate description of tra c ows than that provided by the basic model of tra c assignment, there have been suggestions to impose upper bounds on the link ows. This can be done either by introducing explicit link capacities or by employing travel time functions with asymptotes at the upper bounds. Although the latter alternative has the disadvantage of inherent nume...

An Augmented Lagrangean Scheme for Capacitated Traac Assignment Problems

The inclusion of explicit bounds on the link ows in tra c assignment models has been proposed as a means to obtain a more accurate description of the tra c behaviour than that given by the basic, uncapacitated, model. Although the capacitated problem has the advantage of being numerically more tractable than models involving travel cost functions which tend to in nity as ows approach the link c...

A Gradient Projection Algorithm for Side-constrained Traffic Assignment

An Augmented Lagrangean Approach for the QoS Constrained Routing Problem

Given a directed graph with capacities on each arc and given a set of commodities, the QoS constrained Routing Problem (QCRP) consists in routing each commodity while respecting a endto-end upper bound on the delay for each packet. This problem is NP-hard and we propose an augmented Lagrangean approach to solve it. A flow deviation algorithm as well as a projected gradient method are proposed t...

Lagrangean/surrogate relaxation for generalized assignment problems

This work presents Lagrangean/surrogate relaxation to the problem of maximum pro®t assignment of n tasks to m agents (n > m), such that each task is assigned to only one agent subject to capacity constraints on the agents. The Lagrangean/surrogate relaxation combines usual Lagrangean and surrogate relaxations relaxing ®rst a set of constraints in the surrogate way. Then, the Lagrangean relaxati...