Author: Drew Wicke

Drew Wickehttp://drew.psib.org

Microeconomics

I was learning a bit of micro to help my brother and here is a bit of what I learned.

The economics term for derivative is marginal.  Marginal revenue is the derivative of the revenue function.  Revenue is defined by R(q) = P(q)*q the price at a particular quantity times the quantity sold.  So, R'(q) = P'(q)*q + P(q) is the marginal revenue.  Usually P(q) does not change so P'(q) is zero. Therefore, R'(q) = P(q).  So, marginal revenue is the price I charged for producing one unit (remember P(q) is constant for any q).

Can also have marginal cost.  Which is similar to marginal revenue.

I also learned about elasticity.  Elasticity is the percent that Y changes in response to X changing by 1%.  In general elasticity is define by e = (dY/dX)*(X/Y).  This says the elasticity of Y with respect to X is the derivative of Y with respect to X times X over Y.  So, elasticity is a general thing you calculate for anything.  You just plug the words in for Y and X.  For example, the elasticity of demand with respect to price is: n = (dQ/dP)*(P/Q).  However, the demand curve usually has a negative slope so the derivative is negative.  Economists don’t like the negative so they usually write the elasticity of demand as n = -(dQ/dP)*(P/Q).  Remember D'(p) = (dQ/dP) and D(P) = Q = some equation in terms of P.  Usually, we like our equations to be in terms of one variable so I would substitute like this: n = -(dQ/dP)*(P/D(P)).  So, what does elasticity of demand tell us?  Well, first demand tells us how much a consumer buys at a particular price.  Elasticity looks at how the quantity changes as price changes.  So, 0<=n<1 if the demand for a good at that price is inelastic.  Meaning the quantity demanded doesn’t change radically.  If n > 1 then the demand is elastic meaning if we change the price the demand will change quite a bit.

Another interesting thing I learned was about the market demand residual.  This starts to be interesting because it is taking into account other (possibly identical) businesses.  The market demand residual is defined as Dr(P) = D(P) – So(P) where So(P) is the supply of all the other businesses that are identical and D(P) is the demand of the business that is being examined.  So, if there are n identical business then So(P) = sum(i = 1 to n-1) of Si(P).

Ramsey Theory

Ramsey Theory address problems that ask the question “how many elements of some structure must there be to guarantee that a particular property will hold?”  This is the question that I want to know for brokers.  How many brokers must there be for no price wars to occur.

Very interesting ideas.  I liked the one example on wikipedia Schur’s theorem: for any given c there is a number N such that if the numbers 1, 2, …, N are coloured with c different colours, then there must be a pair of integers x, y such that x, y, and x+y are all the same colour

Prisons as multiagent systems

Wonder how prisoner transport routes are created and scheduled.  Maybe the whole prison system could be a test bed for “smart cities”.  They are just the controlled environment we need.  Wonder how much tech is involved in prisons currently.

Probably MAL could be applied somewhere.  Might be an application area worth looking into.

Maybe the prisoners, guards, cleaning people, ie the people in the building.  Maybe create a simulation of a prison and create a multiagent planner to assist the decision making regarding prisoner transport.  Maybe a social network.  CV for monitoring prisoner rehabilitation process.    With that data a better simulation can be produced. CV can already spot riots before they happen.

Ten holes on a white background

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Above is an exact replica of ten holes on a white background that Nil and I saw today at an art museum.  Only the background was a white wall and the holes were drilled into the wall.

 

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Our contribution to the art world is Eleven holes on a white background :).

Some of the art had these black pieces of tape on the floor surrounding them so if someone crossed the black tap a beep would sound and a security person would tell you to step away from the art.  So, we need a break so we found the average time between someone setting the alarms off :).  It was 40 seconds!  So on average every 40 seconds someone crossed one of those black lines.  They really should have used a brighter color other than black like red that maybe even had words like do not cross.

Smart Logistics and the Knowledge Genesis Group

These are two pretty awesome companies/contractors.  They provide muliagent systems approach to solving real world problems.  They implement real time schedulers and optimization algorithms in the real world and not just as academics.  Pretty cool, too bad they aren’t based in the US (though they do have a branch in Florida).

 

http://www.knowledgegenesis.co.uk/home/what-we-do

http://smartlogisticsinc.com/partnerships/

http://goaleurope.com/2012/02/10/russian-science-put-to-a-commercial-use-real-time-multi-agent-optimization-know-how/

Russia and the rest of Europe are not only doing cutting edge research they are so much more advanced in their logistics and preparedness than the US!  Seems like the US is losing  in the multiagent systems race ;).