Capacitated network design is a crucial problem to telecommunications network planners. In this paper we consider the Multi-Level Capacitated Minimum Spanning Tree Problem (MLCMST), a generalization of the well-known Capacitated Minimum Spanning Tree Problem. We present a genetic algorithm, based on the notion of grouping, that is quite effective in solving large-scale problems to within 10% of...

This study considers the (soft) capacitated vertex cover problem in a dynamic setting. This problem generalizes the dynamic model of the vertex cover problem, which has been intensively studied in recent years. Given a dynamically changing vertex-weighted graph G = (V,E), which allows edge insertions and edge deletions, the goal is to design a data structure that maintains an approximate minimu...

In this paper, we present a state-of-the-art branch-and-cut (B&C) algorithm for the multicommodity capacitated fixed charge network design problem (MCND). This algorithm combines bounding and branching procedures inspired by the latest developments in mixed-integer programming (MIP) software tools. Several filtering methods that exploit the structure of the MCND are also developed and embedded ...

We present a new optimization model for the tactical design of scheduled service networks for transportation systems where several entities provide service and internal exchanges and coordination with neighboring systems is critical. Internal exchanges represent border crossings necessitating changes of vehicles, while the coordination with neighboring systems represents intermodal operations. ...

The fixed-charge capacitated multicommodity network design formulation (CMND) represents a generic model for a wide range of applications in planning the construction, development, improvement, and operation of transportation, logistics, telecommunication, and production systems (Balakrishnan, Magnanti, and Mirchandani 1997 and references therein). In these applications, multiple commodities (g...

Survivability refers to keeping a system partially or fully operational when one or more of its components fail. Survivability in telecommunication networks is crucial, as failure of a network component can potentially bring down the whole communication network, as happened in some real-world cases. Adding redundant network components increases the survivability of a network, but cost of the ne...

We consider Benders decomposition for solving two-stage stochastic programs with complete recourse based on finite samples of the uncertain parameters. define cuts binding at final optimal solution or ones significantly improving bounds over iterations as valuable cuts. propose a learning-enhanced (LearnBD) algorithm, which adds cut classification step in each iteration to selectively generate ...

We address the problem of scheduling unsplittable flows using a number of switches in parallel. This has applications in optical switching and eliminates the need for re-sequencing in traditional packet switching. The use of parallel switches is becoming increasingly popular [1], [2] since it provides a way of building a high-speed switch while overcoming the speedup requirement imposed on the ...

We present novel oblivious routing algorithms for both splittable and unsplittable multicommodity flow. Our algorithm for minimizing congestion for unsplittable multicommodity flow is the first oblivious routing algorithm for this setting. As an intermediate step towards this algorithm, we present a novel generalization of Valiant’s classical load balancing scheme for packet-switched networks t...