NEXCADE

(A) SIMULATION OF RANDOM SINGLE PERTURBATIONS

The second section of the Main Results Window shown below, also allows users to carry out random single
perturbations on the network in terms of destruction of random nodes.

Random Single Perturbation Window

Note that the drop down menu is not relevant here, as the simulation will be carried out on a random node in the network.

On clicking the 'simulate' button for selected node loss, the following page is returned:

Random Single Perturbation Result

As shown above, the program enables monitoring the status of network at each random perturbation.
A total of N independent random nodes are removed [N- network size], one at a time,
and users can download the result of each iteration.

AFFECT OF RANDOM SINGLE NODE PERTURBATIONS :
As shown below, NEXCADE will co-plot all major network attributes for each single random deletion.

In this plot, Network degree (blue), clusters (green) and associated extinctions (red) can be visualized
together for every node perturbed.

NEXCADE allows users to plot the affect upon individual network properties in response to random perturbations, as shown below:

Single Node Perturbation

NEXCADE also allows users to compare how different networks respond to random perturbations, as shown below:

Single Node Perturbation

(B) SIMULATION OF RANDOM SEQUENTIAL CASCADES

The fourth and last section of the Main Results Window shown below, also allows users to
carry out random series of cascading perturbations on the network, and comparison of
network response to the degree based ordered series described here.

Random Single Perturbation Window

On clicking the run button, NEXCADE informs the user about the number of random nodes whose
removal results in complete network collapse.
Users can monitor the status of the initial network at each step of the perturbation, or
get an overview of the change in critical network attributes during the perturbation, and finally
download the raw data of the simulation for further analyses.

In addition, NEXCADE allows users to compare the three distinct co-extinction curves in terms of various network level attributes.
For example, shown below is the affect on Total No. of Extinctions in case of degree ordered (green and red) cascades,
as compared to the random (black) cascade.

Series comparison Result Plot

Similarly, Users can compare the coparative response of the network in terms of Size and edges, as shown below:

Series comparison Result Plot

Note the contrast between the two figures across the three cascades of perturbation.
In case of the 'Highest To Lowest' perturbation sequence (shown in Red), the network collapses completely
when only 20% nodes are perturbed.
However, when nodes are removed in the opposing order ( shown in green),
the network is able to tolerate the removal of almost 98% nodes without undergoing system collapse.

Note that the response to random cascade is always in between that to series ordered cascades.

This completes the tutorial on different kinds of random network perturbation using NEXCADE.

Click here to return to the main tutoral page.