A self-organising mixture network for density modelling

A completely unsupervised mixture distribution network, namely the self-organising mixture network, is proposed for learning arbitrary density functions. The algorithm minimises the Kullback-Leibler information by means of stochastic approximation methods. The density functions are modelled as mixtures of parametric distributions such as Gaussian and Cauchy. The first layer of the network is similar to the Kohonen's self-organising map (SOM), but with the parameters of the class conditional densities as the learning weights. The winning mechanism is based on maximum posterior probability, and the updating of weights can be limited to a small neighbourhood around the winner. The second layer accumulates the responses of these local nodes, weighted by the learning mixing parameters. The network possesses simple structure and computation, yet yields fast and robust convergence. Experimental results are also presente

Spectral properties of the renormalization group at infinite temperature

The renormalization group (RG) approach is largely responsible for the considerable success that has been achieved in developing a quantitative theory of phase transitions. Physical properties emerge from spectral properties of the linearization of the RG map at a fixed point. This article considers RG for classical Ising-type lattice systems. The linearization acts on an infinite-dimensional Banach space of interactions. At a trivial fixed point (zero interaction), the spectral properties of the RG linearization can be worked out explicitly, without any approximation. The results are for the RG maps corresponding to decimation and majority rule. They indicate spectrum of an unusual kind: dense point spectrum for which the adjoint operators have no point spectrum at all, only residual spectrum. This may serve as a lesson in what one might expect in more general situations.Comment: 12 page

An investigation of the corporate responsibility report assurance statements of the Big Four banks in Australia

The corporate responsibility report demonstrates an organisation’s commitment to sustainability. Currently, not much is known about the quality of the assurance statements of the corporate responsibility reports of banks in Australia. This research study fills the gap in the literature by investigating the corporate responsibility report assurance statements of the Big Four banks in Australia. The assurance statements are evaluated against the criteria provided by O’Dwyer and Owen (2005) and Perego and Kolk (2012). The results reveal that although the assurance statements, on average, meet the criteria highly, there are areas that need improvement. Keywords: assurance, bank, AA1000AS, ASAE 3000, ISAE 3000 JEL Codes:G21, M14, M4

Income and happiness across Europe: Do reference values matter?

Using data from the European Social Survey (ESS), we examine the link between income and subjective well-being. We find that, for the whole sample of nineteen European countries, although income is positively correlated with both happiness and life satisfaction, reference income exerts a negative effect on individual well-being, a result consistent with the relative utility hypothesis. Performing separate analyses for some Eastern European countries, we also find some evidence of a ‘tunnel effect’, in that reference income has a positive impact on subjective well-being. Our findings support the view that in environments with stable income and employment, reference income serves as a basis for social comparisons, whereas in relatively volatile environments, it is used as a source of information for forming expectations about future status

Binding potentials for vapour nanobubbles on surfaces using density functional theory

We calculate density profiles of a simple model fluid in contact with a planar surface using density functional theory (DFT), in particular for the case where there is a vapour layer intruding between the wall and the bulk liquid. We apply the method of Hughes et al. [J. Chem. Phys. 142, 074702 (2015)] to calculate the density profiles for varying (specified) amounts of the vapour adsorbed at the wall. This is equivalent to varying the thickness $h$ of the vapour at the surface. From the resulting sequence of density profiles we calculate the thermodynamic grand potential as $h$ is varied and thereby determine the binding potential as a function of $h$. The binding potential obtained via this coarse-graining approach allows us to determine the disjoining pressure in the film and also to predict the shape of vapour nano-bubbles on the surface. Our microscopic DFT based approach captures information from length scales much smaller than some commonly used models in continuum mechanics.Comment: 15 pages, 15 figure

Interplanetary mission design handbook. Volume 1, part 1: Earth to Venus ballistic mission opportunities, 1991-2005

Graphical data necessary for the preliminary design of ballistic missions to Venus is presented. Contours of launch energy requirements, as well as many other launch and arrival parameters, are presented in launch data/arrival date space for all launch opportunities from 1991 through 2005. An extensive text is included which explains mission design methods, from launch window development to Venus probe and orbiter arrival design, utilizing the graphical data in this volume as well as numerous equations relating various parameters

Atomic decomposition and interpolation for Hardy spaces of noncommutative martingales

We prove that atomic decomposition for the Hardy spaces h_1 and H_1 is valid for noncommutative martingales. We also establish that the conditioned Hardy spaces of noncommutative martingales h_p and bmo form interpolation scales with respect to both complex and real interpolations