1. Dynamic Structure Modeling
Advantages:
Increase the Modeling Power
Biological Systems, e.g., adapt to a evolving environment
Engineered Systems, e.g., dynamically adding/removing computing nodes
Deal with Simulation Performance for large scale models

2. An Simple Example addModel(C);
addCoupling(C, COutputPort, B, BInputPort);
removeModel(A);

3. Dynamical Structure Operations
Add Model
Remove Model
Add Coupling
Remove Coupling
Add interfaces (ports)
Remove interfaces (ports)

4. Who initiates a change and what to change
The structure change is controlled by a centralized Executor
Every atomic model can initiate a structure change with operation boundaries
Every atomic model can initiate a structure change for models everywhere in the model tree

5. Operation Boundaries
addModel(…): a model can only add components to its parent coupled model.
removeModel(…): a model can only remove itself and its brothers.
addCoupling(…): a model can only add couplings involving itself, its parent, and its brothers.
removeCoupling(…): a model can only remove couplings involving itself, its parent, and its brothers.
adding/removing ports: a model can only add/remove ports of itself and its brothers.

6. An Demonstrative Example in SimView
variableStructure.CouplingHier

7. Variable Structure Example: Pulse Pipeline One Dimensional Cell Space1 2 3 4 5 6 7 8
initialize the cell space with first, second and last
cells
oneDCell zero = addCell(0,new pulseCell( 0, fireDelay ));
oneDCell one = addCell(1,new pulseCell( 1, fireDelay ));
oneDCell last = addCell(numCells-1,new pulseCell( numCells-1, fireDelay ));
addCoupling( this, "in", zero, "in" );
addCoupling(last, "out", this, "out" );
addCoupling(zero, "out",one,"in");
The advantage of VS is that we do not have to load all of the cells at initialization -- important for large numbers
public void addPipeNeighbor(){
addNeighbor(1,new pulseCell(id+1,10));
addNeighborCoupling(+1,"out","in"); }
add a call in deltext to create a neighbor and its couplings
add neighbor cells as they become active
public void deltext( double e, message x ) {
addPipeNeighbor();
Continue( e );
if ( phaseIs( "passive" ) && somethingOnPort( x, "in" ) )
holdIn( "fire", rg.expon( fireDelay ) ); }
oneDimCellSpace.
pipeLineRand

8. Example: Variable GPT Model
Models can be added/removed at the same digraph
level and levels underneath it, but they can’t be added
to the parent level or from one digraph model into
another digraph model at the peer-level.

9. ForestFire
(a) (b) (c)
(d) (e) (f)

10. ForestFire -- Dynamical Resolution
Simulation using all low resolution cells
Simulation using all high resolution cells
Simulation using dynamic resolution cells