IENG 423 Design of Decision Support Systems Model Based Decision Support Systems 10/10/ Internet as a Decision Support Tool

What are these? What do you call the one on the left? The right? Pasted from fox-a&rls=org.mozilla%3Aen- US%3Aofficial&sa=3&q=toy+car&btnG=Search+images Pasted from ex.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

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 ex.php

How about this? What is the functionality of this model? What might we use it for? Pasted from

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 irefox-a&channel=s&rls=org.mozilla%3Aen- US%3Aofficial&hs=eGt&um=1&sa=1&q=3d+comp uter+models+ares&aq=f&oq=&aqi=&start=0 Pasted from 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 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 system We 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) = P 0 e rt Malthusian Population Growth Model Initial Pop

Example – model energy usage in your apartment You have 5 light bulbs All 5 are 100 watt bulbs You turn them all on and off at the same time So, 5 bulbs * 20 hours/month * 100 watts= 10,000 watt-hours or 10 kwh 10 kwh * $ per kwh = $ ~61¢

Example – model energy usage in your apartment Ok, this works but not very flexible (why?) …or generalizable (why?) So, lets create a new model Electricity cost = (Nbulbs *watts* hours-on)/1000*rate

Example – model energy usage in your apartment Still could be better Electricity cost = Σ(Bwatts i *time i )/1000 * rate Σ(100*5,50*20)/1000 * = 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