A Theoretical Foundation for Count Data Models

The paper develops a theoretical foundation for using count data models in travel cost analysis. Two micro models are developed: a restricted choice model and a repeated discrete choice model. We show that both models lead to identical welfare measures.

Co-operative authoring and collaboration over the World Wide Web : a thesis presented in partial fulfilment of the requirements for the degree of Master of Technology in Computer Systems Engineering at Massey University, Palmerston North, New Zealand

Co-operative authoring and collaboration over the World Wide Web is looking at a future development of the Web. One of the reasons that Berners-Lee created the Web in 1989 was for collaboration and collaborative design. As the Web has limited collaboration at present this thesis looks specifically at co-operative authoring (the actual creation and editing of web pages) and generally at the collaboration surrounding this authoring. The goal of this thesis is to create an engine that is capable of supporting co-operative authoring and collaboration over the Web. In addition it would be a major advantage if the engine were flexible enough to allow the future development of other access methods, especially those that are web related, such as WebDAV, WAP, etc

Rigorous upper bound on the critical temperature of dilute Bose gases

We prove exponential decay of the off-diagonal correlation function in the two-dimensional homogeneous Bose gas when a2ρ is small and the temperature T satisfies T>4πρ/ln|ln(a2ρ)|. Here, a is the scattering length of the repulsive interaction potential and ρ is the density. To the leading order in a2ρ, this bound agrees with the expected critical temperature for superfluidity. In the three-dimensional Bose gas, exponential decay is proved when T−Tc(0)/Tc(0)>5√aρ1/3, where Tc(0) is the critical temperature of the ideal gas. While this condition is not expected to be sharp, it gives a rigorous upper bound on the critical temperature for Bose-Einstein condensation

Fast computation of the matrix exponential for a Toeplitz matrix

The computation of the matrix exponential is a ubiquitous operation in numerical mathematics, and for a general, unstructured $n\times n$ matrix it can be computed in $\mathcal{O}(n^3)$ operations. An interesting problem arises if the input matrix is a Toeplitz matrix, for example as the result of discretizing integral equations with a time invariant kernel. In this case it is not obvious how to take advantage of the Toeplitz structure, as the exponential of a Toeplitz matrix is, in general, not a Toeplitz matrix itself. The main contribution of this work are fast algorithms for the computation of the Toeplitz matrix exponential. The algorithms have provable quadratic complexity if the spectrum is real, or sectorial, or more generally, if the imaginary parts of the rightmost eigenvalues do not vary too much. They may be efficient even outside these spectral constraints. They are based on the scaling and squaring framework, and their analysis connects classical results from rational approximation theory to matrices of low displacement rank. As an example, the developed methods are applied to Merton's jump-diffusion model for option pricing

Clean and green with deepening shadows? a non-complacent view of corruption in New Zealand

New Zealand has long been regarded as a country with little or no governmental corruption. In recent times it has been ranked consistently as one of the five least corrupt countries in the world, on Transparency International’s (TI) Corruption Perceptions Index (CPI). In 2009 and 2011 it was ranked as the single most corruption-free country on the CPI, and in 2012 it shared first place with Denmark and Finland. This paper examines the reasons why historically New Zealand has been largely free of governmental corruption, using widely accepted definitions of what constitutes corrupt behaviour. It goes on to argue that, at least by its own normal standards, the country might now be more susceptible to corruption, for a variety of reasons, in both the public and private sectors, and that more political and administrative attention may need to be paid to this issue. The paper discusses New Zealand’s surprising tardiness in ratifying the United Nations Convention against Corruption, an apparent reluctance that leaves the country sitting alongside other non-ratifying countries which have endemic levels of corruption in all its forms. In this context, the paper also notes some international dissatisfaction with New Zealand’s anti-money laundering legislation, enacted in 2009