Topology of interconnection networks with given degree and diameter
- Authors: Pineda-Villavicencio, Guillermo
- Date: 2009
- Type: Text , Thesis , PhD
- Full Text:
- Description: Doctor of Philosophy
Graphs and subgraphs with bounded degree
- Authors: Teska, Jakub
- Date: 2008
- Type: Text , Thesis , PhD
- Full Text:
- Description: "The topology of a network (such as a telecommunications, multiprocessor, or local area network, to name just a few) is usually modelled by a graph in which vertices represent 'nodes' (stations or processors) while undirected or directed edges stand for 'links' or other types of connections, physical or virtual. A cycle that contains every vertex of a graph is called a hamiltonian cycle and a graph which contains a hamiltonian cycle is called a hamiltonian graph. The problem of the existence of a hamiltonian cycle is closely related to the well known problem of a travelling salesman. These problems are NP-complete and NP-hard, respectively. While some necessary and sufficient conditions are known, to date, no practical characterization of hamiltonian graphs has been found. There are several ways to generalize the notion of a hamiltonian cycle. In this thesis we make original contributions in two of them, namely k-walks and r-trestles." --Abstract.
- Description: Doctor of Philosophy
Optimization based methods for solving some problems in telecommunications and the internet
- Authors: Jia, Long
- Date: 2005
- Type: Text , Thesis , PhD
- Full Text:
- Description: The purpose of this thesis is to develop some new algorithms based on optimization techniques for solving some problems in some areas of telecommunications and the Internet. There are two main parts to this thesis. In the first part we discuss optimization based stochastic and queueing models in telecommunications network corrective maintenance. In the second part we develop optimization based clustering (OBC) algorithms for network evolution and multicast routing. The most typical scenario encountered during mathematical optimization modelling in telecommunications, for example, is to minimize the cost of establishment and maintenance of the networks subject to the performance constraints of the networks and the reliability constraints of the networks as well. Most of these optimization problems are global optimization, that is, they have many local minima and most of these local minima do not provide any useful information for solving these problems. Therefore, the development of effective methods for solving such global optimization problems is important. To run the telecommunications networks with cost-effective network maintenance,we need to establish a practical maintenance model and optimize it. In the first part of the thesis, we solve a known stochastic programming maintenance optimization model with a direct method and then develop some new models. After that we introduce queue programming models in telecommunications network maintenance optimization. The ideas of profit, loss, and penalty will help telecommunications companies have a good view of their maintenance policies and help them improve their service. In the second part of this thesis we propose the use of optimization based clustering (OBC) algorithms to determine level-constrained hierarchical trees for network evolution and multicast routing. This problem is formulated as an optimization problem with a non-smooth, non-convex objective function. Different algorithms are examined for solving this problem. Results of numerical experiments using some artifiicial and real-world databases are reported.
- Description: Doctor of Philosophy
The network paradigm : considering the development of an information technology and telecommunications industy in Ballarat, Victoria with a network perspective
- Authors: Morris, Brian
- Date: 2002
- Type: Text , Thesis , PhD
- Full Text: false
- Description: This thesis considers how applicable is the network paradigm to understanding the development of an information technology and technology industry in Ballarat, Australia.
- Description: Doctor of Philosphy