how to convert the units from "person" to "kit/person"

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anjomshoae
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how to convert the units from "person" to "kit/person"

Post by anjomshoae »

Hi,

I want to model the required amount of consumable relief items (such as water, medicine,etc..) for an evacuation scenario. I developed a simple model based on the following formula:


p(t)=1/(1+EXP(-α*(Time-H))^2)

where Pt is the percentage of the evacuees who have departed by
time t and α and H are model parameters to be calibrated. α gives
the slope of the cumulative traffic loading curve, and H is half loading
time: the time when half of the vehicles in the system are loaded
onto the highway network.


I want to calculate the amount of "required relief items" based on the stock of "population in the shelter.


1. Is my formulation correct in the attached model?
2. what could be the possible units for a multiplier to change "person" to "kit/person"? (this is for the variable "required relief commodities")
3. Can I use the variable "required relief commodities" as demand input to a stock management model, that fulfills this demand? what could be other possible ways to fulfill this demand?
Attachments
Demad formulation 2 based on Logit function.mdl
(3.19 KiB) Downloaded 202 times
Administrator
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Re: how to convert the units from "person" to "kit/person"

Post by Administrator »

I cannot answer 1 and 3.
2. what could be the possible units for a multiplier to change "person" to "kit/person"? (this is for the variable "required relief commodities")
Are you thinking of the correct units here? I'd expect to see a population (measured in people) and maybe kits per person (kit/person), multiply these together to get kits required.
Advice to posters seeking help (it really helps us to help you)
http://www.ventanasystems.co.uk/forum/v ... f=2&t=4391

Units are important!
http://www.bbc.co.uk/news/magazine-27509559
anjomshoae
Member
Posts: 46
Joined: Thu Oct 23, 2014 1:08 pm
Vensim version: DSS

Re: how to convert the units from "person" to "kit/person"

Post by anjomshoae »

Yes, I want to have correct units in my model. attached is the revised version of the model. could you please check and confirm if the units are correct now.

how about the formulation for the rate "leaving the shelter", is the formulation correct?

Code: Select all

(Population in shelter*Fraction of population leaving shelter)/average length of stay in shelter
Also the behavior of the model, do you think looks logical?

regards,
Attachments
Demad formulation 2 based on Logit function.mdl
revised model
(3.43 KiB) Downloaded 187 times
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Joined: Wed Mar 05, 2003 3:10 am

Re: how to convert the units from "person" to "kit/person"

Post by Administrator »

anjomshoae wrote: Sat Jun 16, 2018 5:11 am Yes, I want to have correct units in my model. attached is the revised version of the model. could you please check and confirm if the units are correct now.
You can do this yourself, click the units check tool (or hit CTRL->U).
anjomshoae wrote: Sat Jun 16, 2018 5:11 amhow about the formulation for the rate "leaving the shelter", is the formulation correct?
I cannot tell you if the formulation is correct. In this case, I'd expect one of the following to be correct.
leaving shelter = Population In Shelter / AVERAGE LENGTH OF STAY IN SHELTER
or
leaving shelter = Population In Shelter * FRACTION OF POPULATION LEAVING SHELTER
Advice to posters seeking help (it really helps us to help you)
http://www.ventanasystems.co.uk/forum/v ... f=2&t=4391

Units are important!
http://www.bbc.co.uk/news/magazine-27509559
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