[R-sig-dyn-mod] two questions in a simulation

Dear list,




I am trying a system dynamics simulation with the deSolve package. The model describes the following content:




The knowledge hiding makes people anxious,the anxiety makes people go knowledge seeking, the knowledge seeking behavior increases the obtained knowledge that was hidden, which reduces the anxiety. The problem I encountered are:






The knowledge seeking behavior increased the knowledge people obtained from 0 to 100% of the knowledge, thus, the anxiety reduced to 0. When people obtained 100% of the knowledge, they stop knowledge seeking. However, the knowledge in the background would be updated with some rate, for instance, 1% every 10 time units (days), which makes people have chance to do knowledge hiding again, which further makes the victims of knowledge hiding anxious again. What structure do I need to express this logic?



What is the correct way of getting the interactive effect? Do I just fix the interactive variable to a certain value and run the model again and again to get the results for this value like what we do in sensitivity test? or is there a way to get the interactive effect in a single run of simulation?


I hope I have described my problem clearly. This is my first system dynamics simulation in R. Please give me some suggestions. Thank you very much.


Best regards,


YA