We have constructed a one dimensional exactly solvable model, which is based on the t-J model of strongly correlated electrons, but which has additional quantum group symmetry , ensuring the degeneration of states. We use Bethe Ansatz technique to investigate this model. The thermodynamic limit of the model is considered and equations for different density functions written down. These equation...

The goal of the work reported in this dissertation is to develop methods for the acquisition and reproduction of high quality digital colour images. To reach this goal it is necessary to understand and control the way in which the different devices involved in the entire colour imaging chain treat colours. Therefore we addressed the problem of colorimetric characterisation of scanners and print...

OBJECTIVE Attention Deficit / Hyperactivity Disorder (ADHD) and Chronic Tic Disorder (CTD) are two common and frequently co-existing disorders, probably following an additive model. But this is not yet clear for the basic sensory function of colour processing sensitive to dopaminergic functioning in the retina and higher cognitive functions like attention and interference control. The latter tw...

Observer metamerism was investigated in two colour matching settings. One was the classical large-field bipartite field matching with the use of narrow-band lights. The other was the cross-media setup typical for soft-proofing, with the use of reflective stimuli and two types of computer monitors. In the first experiment, five observers made repeated maximum saturation colour matches with a 6° ...

Very little is known about how animal colour patterns develop. The stripes of the zebrafish provide a tractable a model for colour pattern formation, which now suggests an unconventional patterning mechanism.

The article describes a colour based recognition system with three novel features. Firstly, the proposed system can operate in environments where spectral characteristics of illumination change in both space and time. Secondly, benefits in terms of speed and quality of output are gained by focusing processing to areas of salient colour. Finally, an automatic model acquisition procedure allows r...

We study the generalisation of Baxter’s three-colour problem to a random lattice. Rephrasing the problem as a matrix model problem we discuss the analyticity structure and critical behaviour of the resulting matrix model. Based on a set of loop equations we develop an algorithm which enables us to solve the three-colour problem recursively. PACS codes: 05.20.y, 04.60.Nc

This paper describes a colour-based recognition system with three novel features. Firstly, the proposed system can operate in environments where spectral characteristics of illumination change in both space and time. Secondly, benefits in terms of speed and quality of output are gained by focusing processing to areas of salient colour. Finally, an automatic model acquisition procedure allows ra...

A method based on colour information is proposed to detect defects on ‘Golden Delicious’ apples. In a first step, a colour model based on the variability of the normal colour is described. To segment the defects, each pixel of an apple image is compared with the model. If it matches the pixel, it is considered as belonging to healthy tissue, otherwise as a defect. Two other steps refine the seg...