A Problem Solving Environment for Modelling Stony Coral Morphogenesis

Apart from experimental and theoretical approaches, computer simulation is an important tool in testing hypotheses about stony coral growth. However, the construction and use of such simulation tools needs extensive computational skills and knowledge that is not available to most research biologists. Problem solving environments (PSEs) aim to provide a framework that hides implementation details and allows the user to formulate and analyse a problem in the language of the subject area. We have developed a prototypical PSE to study the morphogenesis of corals using a multi-model approach. In this paper we describe the design and implementation of this PSE, in which simulations of the coral's shape and its environment have been combined. We will discuss the relevance of our results for the future development of PSEs for studying biological growth and morphogenesis

Rollbacks in Time Warp - Analysis and Modelling

This paper presents a study of the interactions between the random number generator used and the run-time behaviour of the parallel Time Warp simulation kernel APSIS. A different rollback length distribution, with a far larger chance of long rollbacks taking place, is observed when the state of the random number generator is not preserved across the rollbacks. An explanation for this phenomenon is provided. An analytical model of the rollback behaviour in Time Warp is developed, for rollback length expressed in either the simulation time or the number of events to be rolled back. The hope is that, once the model is complete, it will be possible to determine under what circumstances it is profitable (not) to preserve the state of the random number generator