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

Successful prediction of horse racing results using a neural network

Most application work within neural computing continues to employ multi-layer perceptrons (MLP). Though many variations of the fully interconnected feed-forward MLP, and even more variations of the back propagation learning rule, exist; the first section of the paper attempts to highlight several properties of these standard networks. The second section outlines an application-namely the prediction of horse racing result

The use of field-programmable gate arrays for the hardware acceleration of design automation tasks

This paper investigates the possibility of using Field-Programmable Gate Arrays (Fr’GAS) as reconfigurable co-processors for workstations to produce moderate speedups for most tasks in the design process, resulting in a worthwhile overall design process speedup at low cost and allowing algorithm upgrades with no hardware modification. The use of FPGAS as hardware accelerators is reviewed and then achievable speedups are predicted for logic simulation and VLSI design rule checking tasks for various FPGA co-processor arrangements

Ground penetrating radar migration with uncertain parameters

The focusing principle of Kirchoff migration is described. This allows the introduction of optical focusing techniques that can be used to focus migration. Three focus measures are described that are useful for optimising migration. Simple optimisation routines are implemented that model uncertainties in the migration parameters. The focus measures are then used as cast functions to be maximised. Results show that these measures are useful in optimising migration when there are uncertainties in the parameter

Image processing applications using a novel parallel computing machine based on reconfigurable logic

Zelig is a 32 physical node fine-grained computer employing field-programmable gate arrays. Its application to the high speed implementation of various image pre-processing operations (in particular binary morphology) is described together with typical speed-up result

Screening for potential effects of endocrine-disrupting chemicals in peri-urban creeks and rivers in Melbourne, Australia using mosquitofish and recombinant receptor-reporter gene assays

Sexually mature male mosquitofish (Gambusia holbrooki) were collected from various sites around Melbourne in 2009 to evaluate the performance of gonopodial indices as a biomarker for endocrine disruption in Melbourne's waterways. The mosquitofish indices assessed were body length (BL), gonopodial length (GL)/BL ratio, ray 4:6 ratio and the absence or presence of hooks and serrae, and these varied between sites. The study was complemented by measurements of estrogenic, retinoid, thyroid and aryl hydrocarbon (AhR) receptor activities of the water. Male mosquitofish were 16.3-21.5 mm in length, and although there was a statistically significant positive relationship showing that bigger fish had longer gonopodia than small fish (r2 = 0.52, p < 0.001), there were few significant differences in GL/BL ratio of fish between sites. Measured estrogenic activity was mostly in the range 0.1-1.7 ng/L EEQ, with one site having much higher levels (similar to 12 ng/L EEQ). Aryl hydrocarbon (AhR) receptor activity was observed in all water samples (7-180 ng/L beta NF EQ), although there was no consistent pattern in the level of AhR activity observed, i.e., 'clean' sites were as likely to return a high AhR activity response as urban or wastewater treatment plant (WWTP)-impacted sites. There was no correlation between measurements of receptor actvity and gonopodial length (GL):BL ratio and BL. We conclude that the mosquitofish gonopodia only fulfills part of the criteria for biomarker selection for screening. The mosquitofish indices assessed were cheap and easy-to-perform procedures; however, there is no baseline data from the selected sites to evaluate whether differences in the morpholical indices observed at a site were a result of natural selection in the population or due to estrogenic exposure

A matched pair of test houses with synthetic occupants to investigate summertime overheating

Summertime overheating is increasingly prevalent in both new and existing UK dwellings. High internal temperatures can be dangerous to vulnerable occupants, disrupt sleep and cause thermal discomfort. The mitigation or exacerbation of overheating through simple occupant interventions like window opening and blind use needs better understanding if homes are to be comfortable and safe in summer without the use of air conditioning. This paper describes the adaptation of two adjoining, semi-detached houses to create a matched pair of test houses for full-scale, side-by-side summertime overheating experiments under real weather conditions. Synthetic occupancy was installed to allow dynamic remote control of actuated windows, motorised curtains, automated internal doors and internal heat gains. The houses were instrumented with calibrated sensors to measure the internal and external environment. These instrumented, matched pair homes have also been used to accurately quantify the effects on energy demand, internal temperatures and air quality of refurbishment strategies, occupant behaviour, and different heating, cooling and ventilation technologies

Overheating in dwellings: a matched pair of test houses with synthetic occupants

Summertime overheating is increasingly prevalent in both new and existing UK dwellings. High internal temperatures can be dangerous to vulnerable occupants, disrupt sleep and cause thermal discomfort. The mitigation or exacerbation of overheating through simple occupant interventions like window opening and blind use needs better understanding if homes are to be comfortable and safe in summer without the use of air conditioning. This paper describes the adaptation of two adjoining, semi-detached houses to create a matched pair of test houses for full-scale, side-by-side overheating experiments under real weather conditions. Synthetic occupancy was installed to allow dynamic remote control of actuated windows, motorised curtains, automated internal doors and internal heat gains. The houses were instrumented with calibrated sensors to measure the internal and external environment. The results of the experiments conducted in summer 2017 will be presented in a future paper. These instrumented, matched pair homes can be used to accurately quantify the effects on energy demand, internal temperatures and air quality of occupant behaviours and different heating, cooling and ventilation technologies