Caught Active Walkers
  A discrete implementation on a lattice of the Active Walker Model is presented. After the model's validity is shown in simple simulations, more complex simulations of walkers passing consecutively a lattice from an arbitrary starting point at the left border to a random destination on the right border are presented. It is found that walkers may be caught at a certain position by bouncing back and forth between two contiguous lattice sites. The statistical characteristics of this catchment effect are being studied. The probability distribution of the number of walkers having passed the lattice before the catchment occurred shows a exponential decrease to higher numbers. Furthermore, the influence of some parameters of the model on the catchment phenomenon is discussed. Position and height of the maxima of these distributions show a linear dependency on a parameter. 
S. Schoellmann