Category Archives: simulation

Censorship Machine



Machines can take on many forms, including this one which is flat and would be formally described by a network of activity nodes and arcs among them. The above example is a machine (or automaton) that is defined by flow, as are all automata. The automaton models the censorship process in Iran beginning with the Supreme Leader and then cascading down to the enforcers. This machine is constructed by The Annenberg School for Communication at the University of Pennsylvania. There is a complete description of the process, with the above figure at its original resolution at their web site. Nodes are points of control and arcs probably carry both control and data flow. Curiously, there is very little feedback in this architecture (only at the very end). There is also an interesting correlation between the abstract semantics of machines and Iran's censorship process: power flows from top to bottom (both literally and figuratively). Machines of this sort are a bit different than those in some of the other posts because they are often called models--specifically simulation models. To be more precise, this is a simulation model of the censorship process.

Energy Flow and Food Consumption

I had a discussion online with Ray Winstead who recently retired from the Indiana University of Pennsylvania in Biology. Ray has a page which I came across and found a diagram which is most compelling both for its biological meaning as well as the design (created by William Standaert):


The design is a flow model which receives energy in the form of sunlight and this energy undergoes a "food chain" transformation. The transformation begins with producers (e.g., plants) which are eaten by herbivores, which are in turn eaten by carnivores, to end the chain with the top carnivores (e.g., humans). There are actually 2 sub-chains in this diagram: one for consumers of live material, and the other for detritus. These types of models can be simulated: common model types used by ecologists include Odum graphs, System Dynamics, and compartmental models. Further information with a more abstract model can be found in the Wiki link on energy flow.