IENG 423 Design of Decision Support Systems

Model Based Decision Support Systems

04/19/23 1Internet as a Decision Support Tool

What are these?

What do you call the one on the left?The right?

Pasted from <http://images.google.com/images?gbv=2&hl=en&client=firefox-a&rls=org.mozilla%3Aen-US%3Aofficial&sa=3&q=toy+car&btnG=Search+images>

Pasted from <http://www.hobbyplace.com/plastics/carsindex.php>

What’s the difference?

Why do most of us these two object in different categories?

How about this?

What do we use these things for?What makes them different from a toy?What is its utilize?

Pasted from <http://www.upscaleinc.com/presentation/Promenade.asp>

Models

It represents the object that it is intended to portray……in some important functional way… it has replicated some functional aspect of the object

Models

Models can represent objects that are: Concrete or theoretical Real or imagined Past, current, or… Future – the way things will be.

Models

What is the functionality of this model?What can it tell us? Pasted from <

http://www.hobbyplace.com/plastics/carsindex.php>

How about this?

What is the functionality of this model?What might we use it for?

Pasted from <http://www.upscaleinc.com/presentation/Promenade.asp>

Models – made in a computer

Architectural,Engineering, Interior Design models

What can we do with this that we could not do with physical models?

Computer Models

Ares Space Ship

Pasted from <http://images.google.com/images?hl=en&client=firefox-a&channel=s&rls=org.mozilla%3Aen-US%3Aofficial&hs=eGt&um=1&sa=1&q=3d+computer+models+ares&aq=f&oq=&aqi=&start=0>

Pasted from <http://images.google.com/images?hl=en&client=firefox-a&channel=s&rls=org.mozilla%3Aen-US%3Aofficial&hs=eGt&um=1&sa=1&q=3d+computer+models+ares&aq=f&oq=&aqi=&start=0>

Computer Models

Understanding biology

Pasted from <http://images.google.com/images?hl=en&client=firefox-a&channel=s&rls=org.mozilla%3Aen-US%3Aofficial&hs=eGt&um=1&sa=1&q=3d+computer+models+ares&aq=f&oq=&aqi=&start=0>

A computational model

A computational modeling system for simulating neural behavior at the cellular level using Neuroview. The images shown below are products of work done at WVU by G. Spirou, F. Van Scoy, F. Chirla, D. McLaughlin and G. Goltukhuhyan.

What is a model?

For our purposes A representation of a system that

replicates or imitates some functionality of the system

Why are models useful to us in decision support?

We can observe and try to understand the behavior of the systemWe can understand how the system will respond to changes – In inputs, Decision alternatives In context - different scenarios

Example…

Population Growth Maltusian

Growth Model

P(t) = P0ert

Malthusian Population Growth Model

Initial Pop 1000 0.1

1 1105

2 1221

3 1350

4 1492

5 1649

6 1822

7 2014

8 2225

9 2459

10 2718

Example – model energy usage in your apartment

You have 5 light bulbsAll 5 are 100 watt bulbsYou turn them all on and off at the same timeSo, 5 bulbs * 20 hours/month * 100 watts=

10,000 watt-hours or 10 kwh 10 kwh * $0.0663 per kwh = $0.6063

~61¢

Example – model energy usage in your apartment

Ok, this works but not very flexible (why?)…or generalizable (why?)So, lets create a new modelElectricity cost = (Nbulbs *watts* hours-on)/1000*rate

Example – model energy usage in your apartment

Still could be better

Electricity cost = Σ(Bwattsi*timei)/1000 * rate

Σ(100*5,50*20)/1000 * 0.0663= 10¢

But remember…

“All Models Are Wrong Some Models Are Useful”

….generally attributed to the statistician George Box

Have a nice day!

That’s all I have to say about that