Thursday, August 27, 2009

IEOR Tools update: New Tools links

I just thought I would bring to the attention that I have added a few links to the IEOR Tools Web Forums and Resources.

The first is Open Source Mathematics. This site is devoted to sharing Open Source mathematical software and developments. I would hope that this site develops as this is an area I would like to see increase greatly. It seems the site owner is definitely a proponent of Sage. That is a good segway to my next link.

The next link is Sage. Sage is an open source mathematics software system. Sage is very similar to Matlab, Mathmatica, or NumPy. From the Sage website...

Sage can be used to study general and advanced, pure and applied mathematics. This includes a huge range of mathematics, including algebra, calculus, elementary to very advanced number theory, cryptography, numerical computation, commutative algebra, group theory, combinatorics, graph theory, exact linear algebra and much more. It combines various software packages and seamlessly integrates their functionality into a common experience. It is well suited for education, studying and research.

Be sure to look at the Sage tour for more information and functionality.

Next link from is Open Source Engineering Tools. As you can guess there is a variety of open source tools for the Engineering practioner. Unfortunately it is sorely lacking in mathematical and numerical applications. I might volunteer and help out where I can. I am sure they would want the extra assistance. As an aside here is a article about and their concept.

The last link is A self described open source engineering portal for news, links, resources of open source engineering software. The list is very complete for most types of engineering disciplines. Although I would like to see more Industrial Engineering at this site as well. Very good and looking forward to seeing more developments at

Wednesday, August 26, 2009

Diagramming with Dia tutorial has a great tutorial on the diagramming tool Dia. Dia is a free and open source diagramming tool that draws its inspiration from Microsoft Visio. From the Dia website...

It currently has special objects to help draw entity relationship diagrams, UML diagrams, flowcharts, network diagrams, and many other diagrams. It is also possible to add support for new shapes by writing simple XML files, using a subset of SVG to draw the shape.

It can load and save diagrams to a custom XML format (gzipped by default, to save space), can export diagrams to a number of formats, including EPS, SVG, XFIG, WMF and PNG, and can print diagrams (including ones that span multiple pages).

Dia is available to download for Windows and Linux. The tutorial even explains how to download and install for each operating system.

The Industrial Engineer can really use Dia for a number of projects. Just to name a few include flowcharting process flows, diagramming models of queues, and mind mapping exercises.

The tutorial does a great job of detailing the steps to get projects started. I find that tutorials with pictures or screenshots tend to be the best. This tutorial has plenty of screenshots to guide the beginner diagrammer.

As I have mentioned before there are great alternative IEOR Tools available in the free and open source community. Give Dia a try and let me know about your experience.

Monday, August 24, 2009

The flaw of averages

An interesting article from the Washington Times about a new book "The Flaw of Averages" by Sam L. Savage. Savage says that basing decisions on averages alone can be a dangerous assumption. In fact, the assumption the decision is going to be based is going to be wrong half the time. From the article and I believe this to be well said

It is the flaw of averages that causes businessmen, engineers, generals and others to underestimate risk in the face of uncertainty.
How true is that statement. As a practitioner of Operations Research in the business world I often am not just providing solutions for my employer but also playing referee. I'm not sure how many times I have had to tell a manager or associate to recheck their assumptions before they bring their analysis up the chain of command. One of my previous bosses had a great phrase that he would tell me, "Does it pass the smell test?" In other words can you step back and say with certainty that your assumptions are right on the mark.

Sam Savage has a great point about flawed analysis based on assumptions alone. The crucial emphasis should be on the assumptions themselves. All good analysis should make sure that the assumptions are correct and reflect the real world implications. The article cites the recent problems with the home mortgage crisis. A lot of assumptions in the risk models that gave AAA ratings to mortgage-backed securities were not taking into account future market cycles and risk.

So should averages be used in analysis? By all means, no pun intended. Statistical inferences and generalities require average value of numerical populations. Averages do have their place in analysis when comparing samples. Yet so do standard deviations, variance, correlation, and so on. There is more to risk modeling than just the simple average.

Tuesday, August 18, 2009

Beware the Zombie attack according to latest models

Thanks to the expert mathematical minds at the University of Ottawa they have found that in the event of a zombie attack we would be wiped out rather quickly. Their answer is to attack "quickly and aggressively" according to the study. Their report was published in the book "Infectious Diseases Modeling Research Progress". Treehugger and Wired also covered this story.

Apparently the modeling research was developed to study unfamiliar diseases. The modeling can be used to find the affects of swine flu and SARS. And in this case apparently from the affects of zombie attack outbreaks! Perhaps we should all be prepared.

Thursday, August 6, 2009

Social Networks and optimal contacts

The Open Road blog has an interesting article about interconnecting "meta-address books". In this article Matt Asay explains how open source companies are trying to optimally connect people together by the meta-data they place in the internet cloud such as using Open-Xchange.

One such example they describe is PeopleMaps from 7-Degrees. By leveraging what they know about someone online they can use that data to connect with other people of related interests, business, and other potential connections. According to the 7-Degrees website they use their own industry-leading path-finding algorithms to enable the connections between the users.

Perhaps Operations Research has a big future with social networks.