Ant colony system (ACS) is a combinatorial optimization method motivated by the behaviour of real ants. In this paper, we present a novel image coding method based on ACS vector quantization of groups of wavelet coefficients. The generation of codebook using ACS is facilitated by representing the coefficient vectors in a bidirectional graph, followed by defining a suitable mechanism of depositi...

The maximum intercluster distance and the maximum quantization error that are minimized by the MinMax algorithm are shown to be inappropriate error measures for color image quantization. A fast and effective (improves image quality) method for generalizing activity weighting to any histogram-based color quantization algorithm is presented. A new non-hierarchical color quantization technique cal...

We comment on Linde’s claim that one should change the sign in the action for a Euclidean instanton in quantum cosmology, resulting in the formula P ∼ e+S for the probability of various classical universes. There are serious problems with doing so. If one reverses the sign of the action of both the instanton and the fluctuations, the latter are unsupressed and the calculation becomes meaningles...

Introduction The interest for canine semen preservation and artificial insemination (AI) is steadily increasing worldwide, yet comparatively few studies are published each year within this field, and it is particularly difficult to find data from artificial inseminations using fresh semen, or semen preserved according to various methods for chilling, or freezing and thawing, and also comparing ...