Networks

Point-to-point vs. hub-and-spoke. Questions of network design are real and involve many billions of dollars. Yet little is known about optimising design - nearly all work concerns optimising flow assuming a given design. This foundational book, first published in 2007, tackles optimisation of network structure itself, deriving comprehensible and realistic design principles. With fixed material cost rates, a natural class of models implies the optimality of direct source-destination connections, but considerations of variable load and environmental intrusion then enforce trunking in the optimal design, producing an arterial or hierarchical net. Its determination requires a continuum formulation, which can however be simplified once a discrete structure begins to emerge. Connections are made with the masterly work of Bendsoe and Sigmund on optimal mechanical structures and also with neural, processing and communication networks, including those of the Internet and the World Wide Web. Technical appendices are provided on random graphs and polymer models and on the Klimov index. Review of the hardback: '... a remarkable book ... a pleasure to read ... plenty of interesting results, ideas and inspiration.' Hartmut Noltemeier, Zentralblatt MATHTour d'horizon; Part I. Distribution Networks: 1. Simple flows; 2. Continuum formulations; 3. Multi-class and destination-specific flows; 4. Design optimality under variable loading; 5. Concave costs and hierarchical structure; 6. Road networks; 7. Structural optimisation: Michell structures; 8. Structures: computational experience of evolutionary algorithms; 9. Structure design for variable loading; Part II. Artificial Neural Networks: 10. Models and learning; 11. Some particular nets; 12. Oscillatory operation; Part III. Processing Networks: 13. Queuing networks; 14. Time-sharing networks; Part IV. Communication Networks: 15. Loss networks: optimality and robustness; 16. Loss networks: stochastics and self-regulation; 17. Operation of the Internet; 18. Evolving networks and the World-wide Web; Appendix 1. Spatial integrals for the telephone problem; Appendix 2. Bandit and tax processes; Appendix 3. Random graphs and polymer models; References; Index.