Some questions

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behess
Posts: 2
Joined: Monday 26 September, 2016 - 20:36

Some questions

Post by behess »

Hello,

I‘ve got a list of questions while I was creating a modell. I tried a lot, but nothing was successfull.

1. Is it possible to set an arrival distribution for the generators? In my case I have to implement an event which takes eight hours. From the beginning up to the middle of the event there should be an increasing arrival rate (arrivals of agents per time). Then it should decrease. The last two hours no agents should be generated. Next to this requirements I have a limit of the number of agents.

2. In my simulation agents can visit different places like at a market. Is there a way to implement it a bit more dynamically in contrast to the activity list of the activity routes, where agents strictly do the activities in order of the list? For example it should be possible that the agent visits between 1 to 5 places and then does another activity or not.

3. I miss an action timer which can trigger elements periodically:
Once I wanted to model a crosswalk with traffic lights (street as obstacle with hight = 0 and pedestrian crossing as a passageway). Do you have a recommended way with a queue to implement it? I tried it with an action timer and switching the availability of the passageway.
At the first point there are events which end at predefined times. So the agents in some commercial or waiting areas should be triggered every 30 minutes to leave the location. The events are open. So the agents don‘t need to start their activity at the same time.

4. I already wrote that in my model there are streets which are implemented as obstacles. Is it possible in the case of an evacuation to remove these obstacles, so that the agents could also use the street for routing?
Surely the way with obstacles isn‘t the best way. Is it possible to create a walking area which can be switched off and on and can be set with an avoidance factor? Sometimes people cross streets although there isn‘t a crosswalk.

Thank You!
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marlies
Posts: 301
Joined: Monday 17 January, 2011 - 09:28

Re: Some questions

Post by marlies »

Hi,

I''ll start with your question nr 3 first: Activity Locations do have the possibility to trigger agents periodically. See attached example model: agents go to the waiting area and get the activity time "wait until triggered" which is -1.

Then: go to the Availability of the waiting area. Here I defined a schedule that repeats every 10 minutes (upper part). In the lower part you can specify what should happen when the availabilty changes (Trigger on start). In this case I chose: trigger all waiting agents in current activity location. That will make all agents inside the area start walking.

You could use this availability also to schedule a traffic light and trigger the agents in connected corridors (2nd example).

Will come back to your other questions later.

Kind regards, Marlies
Attachments
20160927_TrafficLight.mod
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20160927_EventTrigger.mod
(137.86 KiB) Downloaded 208 times
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marlies
Posts: 301
Joined: Monday 17 January, 2011 - 09:28

Re: Some questions

Post by marlies »

Hi,

To come back to your other questions:

1a. You can set the limit of the number of agents in: Agent Generator > Tab General > Max nr of agents.
1b. You can make an arrival distribution in multiple ways. See attached model ArrivalDistribution for a suggestion that might work for you:
- Go to the agent generator > the arrival list contains 8 arrivals, 1 for each hour. The nr Agents column specifies the number of agents per hour.
- then go to the tabe general of this generator and check the setting: Delay Time. Here I defined: uniform between 0 seconds and 1 hour. What will happen is: agents will be generated per hour according to the arrivallist. The delay time will add a delay to each individual agent. This will make them entering the model divided over the hour interval.

2. This could also be done in multiple ways. For an example see attached model Market. Then have a look at the agent input > activities > activity MarketStep2. When you look up the tab Locations of this activity you'll see that the percentages sum up to 50%. This will have the effect that 50% of the agents will get an location assigned according to this distribution. The other 50% will just skip this step in the route. You can add more steps like this to the route.
Another way could be as in example Market_Option2:
- go to the agent generator and check the creation trigger in the arrivallist --> each agent will get a label named NrOfStalls with a value between 1 and 5.
- go to the agent input > activities . MarketStall and check the exit trigger. This script does the following: increase a label on the agent when it visited a stall. Then check if the agent visited already as many stalls as defined in the label NrOfStalls. If it is smaller than te required number: the agents "steps back" in the route and will execute the activity market stall again.
This 2nd option requires a bit more scripting, but gives you a compact model.


4. The best way to model this is using passageways instead of obstacles. The direction of a passageway can easily be updated using the action timer from unavailable to bidirectional. Also PassageWays do have a setting discomfort factor which can be used to make a path less attractive.

Hope this helps.

Kind Regards,

Marlies
Attachments
20160927_Market.mod
(161.58 KiB) Downloaded 204 times
20160927_Market_Option2.mod
(160.18 KiB) Downloaded 200 times
20160927_ArrivalDistribution.mod
(129.49 KiB) Downloaded 224 times
behess
Posts: 2
Joined: Monday 26 September, 2016 - 20:36

Re: Some questions

Post by behess »

Hallo Marlies,

thank you a lot! Your answers are very helpful. But I still have a problem:
I tried to rebuild your traffic lights solution, but I don't see what's wrong.
Can you have a look at my model?

Thanks!
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20160928_TrafficLights2.mod
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marlies
Posts: 301
Joined: Monday 17 January, 2011 - 09:28

Re: Some questions

Post by marlies »

Hi,

I guess that's because you might have missed a step that I didn't mention explicitly. When you go:
- one of the entries to the left and right in the model.
- right click and go to tab location
- go to exit trigger

There you'll find a line of code that sends the agents into the indicative corridors that make the agents queue for the traffic lights.

This code could be in other locations/elements as well. Imagine a bigger environment where agents walk through the model based on shortest path. Somewhere on the route they cross a road where they should wait for traffic lights. You could model that as follows:
- Add an action area near the traffic light location.
- In the entry or exit trigger of that action area send the agents into the corridor. Use the predefined logic {**Follow indicative route**}

Regards, Marlies
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