Swarm Intelligence Homework 1Swarm Intelligence Homework Copyright 2011 All rights reserved Mark Polczynski ENMA 6060

2Swarm Intelligence Homework Homework Part 1 – Barbaric Ants The ants that were building cemeteries in the swarm intelligence lecture were a very civilized species of ant. However, their barbaric cousins do not take the time to haul dead ants to a cemetery. All these barbaric ants care about is getting dead ants out of the high-rent districts in the middle of the ant hill. They then drop the dead ants anywhere in the surrounding countryside, as opposed to dropping them in a cemetery. Your assignment is to create a state transition diagram that mimics this barbarous and behavior. See next slide for hints on how to do this.

Swarm Intelligence Homework3 Some hints: Your barbaric ant has just three states: Walking around inside the nest carrying a dead ant Walking around inside the nest not carrying a dead ant Walking around outside the nest not carrying a dead ant. It might seem that there is a state called: Walking around outside the nest carrying a dead ant But your ant drops its dead ant as soon as it leaves the nest, so never actually spends any time in this state. Your ant experiences three conditions: Walk out of nest Walk into nest Bump into dead ant Your ant performs three actions: Pick up dead ant Drop dead ant Keep walking around Use these hints to build your state transition diagram.

Swarm Intelligence Homework4 Homework Part 2 – Optimizing Coefficients Our PSO lecture presented three coefficients used to calculate particle velocity changes: w, cp, and cg. In general, we’d like to make these values as large as possible while still having the particles converge on a solution to the problem. Yu will use Excel file named Ant3H.xls (included in the.zip folder for this swarm intelligence lecture and homework) to explore how these coefficients impact the stability of the swarm. On the Results worksheet, there are two cells where you can enter values for these coefficients. The spreadsheet automatically calculates random starting values for three particles.

Swarm Intelligence Homework5 Homework Part 2 – Optimizing Coefficients When you enter the coefficient values and press the F9 key, the Calculation worksheet of the file calculates 100 iterations of positions for the three particles. The results are shown on the plot on the Results page. For this example, we see that two of the particles settle down, but the third appears to be unstable. Your goal in this part of the homework is to find w, cp, and cg values that cause all three particles to become stable by 100 iterations.

Swarm Intelligence Homework6 Homework Part 2 – Optimizing Coefficients The Results sheet contains a table for your to record your results. For each cell in the table you will enter the associated w cp, and cg values, and then press F9 up to 50 times to check for stability. If the combination is stable, enter Y, otherwise enter N. NOTE: This issue of whether or not all three are stable is not always clear- cut, so just use your judgment – you’ll get a feel for this after a few trials. After completing your table, submit your entire Ant3H file to D2L.