Homework

Bot foraging

In this assignment, you'll analyze the foraging behavior of two classes of bots. The NetLogo code has already been written; you won't have to WRITE any new code this week, but you will have to READ the code and understand it.

Here's the NetLogo code for the demo program: hw05_forage.nlogo.

Answer the questions found on the 'Assignment' tab and email your responses to mcb419@gmail.com with 'hw05' in the Subject line.

This assignment is due by 11:59PM (midnight) on Tue, Feb 24.

Assignment

You can access a copy of the assignment file HERE, or copy and paste from the text below.

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MCB 419 Homework 5 (Spring 2009)

When you've finished answering all the questions, email a copy 
of this file (hw05.txt) with your responses as PLAIN TEXT in
the main body of the email message. 

Email to mcb419@gmail.com with 'hw05' in the Subject line. 

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Bot Foraging Demo


Run the simulation and refer to the NetLogo code to answer
these questions.

SENSING

1. Unlike previous examples, the patches don't have an 
an 'intensity' or 'concentration' variable. Explain 
how the bot sensors are able to respond to the green food 
pellets in this simulation.

2. What is the power-law relationship between sensor 
activation and distance of a food pellet?

3. The sensors have a finite sensing range. What is the 
maximum distance that a food pellet can be detected?

4. The sensors have a finite angular acceptance. How
many degrees of angular coverage do the sensors provide? Can
the bot sense a food particle that is behind it?

FOOD CONSUMPTION, METABOLISM

5. Run the simulation for about 1000 ticks. Note that the bots
are not all the same size.  What is the relationship between bot 
'energy' and bot 'size' in this simulation?

6. How much energy does a bot gain when it consumes a food pellet?
How much energy does it lose per tick when not consuming food?
On average, how often does a bot need to consume a food pellet in
order to just "break even"?

7. What happens to a food pellet after it is consumed?  How many
ticks elapse before the pellet can be consumed by another bot?

BOT REPRODUCTION, DEATH

7. How much energy does a bot need to accumulate before it can 
reproduce?  When a bot does reproduce, how many offpsring does
it have?  How is the parent bot's energy distributed between 
itself and its offspring?

8. How much energy is a baby bot born with?  At what energy level
will a bot die?  Giving the basal metabolic rate from #6 above, how
long would a baby bot live (in ticks) if it doesn't find food.

BEHAVIOR

9. What class of Braitenberg vehicle controller is implemented by
the red bots?  Are connections between sensors and motors crossed
or uncrossed? excitatory or inhibitory?

10. In your own words, without using NetLogo code, describe the
control strategy that is implemented by the yellow bots. How do they
behave when they don't have sensor data? How do they behave when
sensor data is available?

11. Run the simulation for about 5000 steps. When class of bots
(red or yellow) seems to have the advantage?  What factors do you 
think contribute to the relative performance advantage of one class 
over the other?  

12. The yellow bots sometimes seem to 'flock' or 'school'
together. What do you think explains this apparent collective 
behavior?


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END OF THE ASSIGNMENT
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Solution

No NetLogo code to post this week.