Individual-based models of schooling in fish have demonstrated that, via processes of self-organization, artificial fish may school in the absence of a leader or external stimuli, using local information only. We study for the first time how body size and body form of artificial fish affect school formation in such a model. For a variety of group sizes we… (More)
In fish schools the density varies per location and often individuals are sorted according to familiarity and/or body size. High density is considered advantageous for protection against predators and this sorting is believed to be advantageous not only to avoid predators but also for finding food. In this paper, we list a number of mechanisms and we study,… (More)
In this paper, we investigate in which ways a particular behaviour can be achieved with simple mechanisms without being explicitly encoded. It is suggested that enrichening the overall behaviour of an agent in such a way simplifies the creation of intelligent agents. We focus on obstacle avoidance as one particular kind of such a behaviour by an agent. We… (More)
In mammals, circadian rhythms are driven by a pacemaker located in the suprachiasmatic nuclei (SCN) of the anterior hypothalamus. The firing rate of neurons within the SCN exhibits a circadian rhythm. There is evidence that individual neurons within the SCN act as circadian oscillators. Rhythm generation in the SCN was therefore modeled by a system of… (More)
In two simulation models the benefit of schooling under predatory pressure is investigated. It appears that if a predator cannot become confused by prey, grouping is seldom beneficial. If prey, however, can confuse a predator, schooling appears to protect prey under a whole range of parameters. Using an evolutionary approach we found that, in the case of a… (More)
In ASIC design, arithmetic components are usually selected from tool-and technology-dependent libraries providing very limited flexibility and choice of circuit structures. With the possibility of parameterized structural circuit descriptions at the gate-level in VHDL, versatile circuit generators can be implemented which are highly independent of tool… (More)
This article deals with dynamical systems depending on a slowly varying parameter. We present several physical examples illustrating memory eeects, such as metastability and hysteresis, which frequently appear in these systems. A mathematical theory is outlined, which allows to show existence of hysteresis cycles, and determine related scaling laws.