On the Failed Airplane Bombing Attempt

December 31, 2009

When geese “attacked” US Air Flight 1549, and Captain Sully Sullenberger landed the plane in the Hudson river, Americans were overjoyed that disaster had been averted.   When Abdul Mudallah ignited an explosive device on Northwest Flight 253, and no one was injured, Americans spent the next week afraid, with countless criticisms of our government (many of which were justified).  In reality, we should all be very thankful.

First of all, we should be thankful that disaster was averted.  This was great news.  We should also be thankful because we have learned a great deal of what went wrong, and security will improve in the future. Al Qaeda is not likely to succeed if they use the same technique again.  And it takes lots of time to develop new techniques.

I understand why people were so upset.  This event revealed that we were not nearly as safe as we hoped we were, and it revealed that the government is still not sharing information about terrorism well enough.  In other words, the event was the messenger of “bad news.”  Since we couldn’t “shoot the messenger”, Americans sought out others to shoot.

But we really have much to be thankful for.  And the Department of Homeland Security has their work cut out for them.  We all hope that this department has learned a lot of how to prevent the next incident.

Side note to Janet Napolitano:  it really is OK to be honest the first time around.  But other than your first statement about how our security system works, you are doing a heck of a job.

Side note to Dick Cheney:  we are getting very tired of seeing the Mr. Hyde part of your personality. (Perhaps Obama likes this side, since you constantly remind Americans of why voting for Obama was a good idea.)  When will we see the Dr. Jekyll side again?  Please let this side out more frequently.  It seems that we only see it when you talk about your daughter.

Side note to Senate Republicans:  Thanks to you, we still don’t have a head of the Transportation Security Administration (TSA).  “Advise and consent” should not mean “prevent the President from running the Executive branch.”


Traveling Incognito

December 18, 2009

Sarah Palin, in a recent vacation trip to Hawaii, wore a “McCain for President” visor, but crossed out the words.  Her explanation was:  “I Sharpied the logo out on my sun visor so photographers would be less likely to recognize me”.  So, if I understand correctly, she thinks that photographers recognize her by her logo instead of the way she looks.  Or perhaps she thought that crossing out the logo would make her invisible.  In any case, despite all these strenuous efforts at traveling incognito, she was recognized.  Who could have guessed that photographers would see through her clever ploy?  (Perhaps they relied on mathematical modeling approaches.)

How to make mammogram testing cheaper and more effective.

December 16, 2009

New recommendations concerning mammogram testing have upset a lot of people.   Previously, doctors recommended that women be tested yearly starting at age 40. The new recommendations say that most women should start mammogram testing at age 50, and only do it every other year.  The analysis relied on the following empirical result: one cancer death is prevented for every 1,904 women age 40 to 49 who are screened for 10 years, compared with one death for every 1,339 women age 50 to 59, and one death for every 377 women age 60 to 69.  (These recommendation make sense, as pointed out by Mike Trick.)   However, if the ratio of cancer deaths prevented per mammogram could be improved for women aged 40, then mammograms would be recommended.

What this highlights is the importance of a cheap preliminary test with reliability that is pretty good.   For example, suppose that there was a test for which no women with breast cancer had false negatives, and where 1 out of 10 women with no breast cancer had a false positive.  With such a test, approximately 90% of women would be screened out as negative, with all of them having no cancer.  The remaining 10% would test as positive, with the vast majority of them being false positives.  These women would be given mammograms.  (Women would need to be reassured that the preliminary test is not a test for cancer but a test on who should be screened using mammograms.)    Since only 1/10th as many women would be given mammograms, this would result in cancer death prevented for every 190 women being tested, a huge improvement over the current system, with huge savings in terms of health outcomes and dollars.

Even if the test had a false negative rate of 10%, the prevention of cancer deaths would be almost as high.  There would be 1 cancer death prevented for approximately 210 mammograms.  Unfortunately, the false negative could lead to 1 cancer death for every 17,000 women not given mammograms (because of a negative test.)   At the same time, it would eliminate the health risks of mammogram testing for 17,000 women who didn’t have cancer.

The conclusion is that a cheap test with pretty good reliability (say around 90%) can dramatically improve the health outcome of mammogram testing,  while dramatically decreasing the cost of health care.   The NIH should dedicate research funding to find such tests.

To the Secret Service: count your blessings.

December 6, 2009

The Salahis crashed the state dinner in honor of the Indian Prime Minister.  I’m not normally a pollyanna (in fact, I’m rarely a pollyanna), but I view this as good news.  Here is why:  the secret service had a serious flaw in its operations, one that exposed the President to danger.  The Salahis, who were of no danger to the President, exposed the flaw and permitted it to be fixed.

Admittedly, it would be better if there were no flaw to begin with.  But conditioned on there being a flaw, it was very good news that it was revealed and fixed.  Incidentally, no one in the media seems to have observed that the nation owes some gratitude to the Salahis since their actions have improved the protection of the President.

Having said that, I also think that the Salahis should be put in jail for lying to the Secret Service.  They may claim that they think they were invited; however, unless they are totally delusional, they knew better.   And while I feel gratitude that the President will be better protected, I also think it is appropriate to punish those who violate federal crimes, especially ones designed to protect the President.

The advantage of making papers harder to understand

September 27, 2009

When I was a college student, a professor of logic once asked us to write a brief paper on a specified topic, which I no longer remember.  I do remember that I didn’t understand the question that we were supposed to address and had no clue what to write.  So I carried out an experiment.  I wrote something such that each sentence appeared to make sense, but so that the paper did not make any sense when taken as a whole.  (Think “Sarah Palin’s speeches” but with crisper logic.)  My experiment was successful as far as I was concerned.  I got a “B.”  My conjecture is that it would have taken the professor too much time to see through my lack of logic, and it was easier to give it a reasonable grade.  (Warning to current students:  do not try this approach with me.)

In today’s Boston Globe, there is a brief article entitled  “You’d sound smarter if you wrote less clearly.” It’s about David Hakes, an economics professor, who simplified a complex argument in mathematical economics.  Hakes explained, ”We managed to reduce the equations in the paper to six. At this stage the paper was perfectly clear and was written at a level so that it could reach a broad audience.”   When the paper was rejected for being “self evident”, Hakes and his co-author decided to make his work less readable and much more complex mathematically, with no added value.  Hakes later wrote ”I personally could no longer understand the paper.”  It was now acceptable to the referees and published.

Hakes’ point extends to Operations Research and other fields that rely on mathematics.    Referees often do not like simplicity because it may make a paper sound “obvious”, and no referee wants to accept a paper that is obvious.  Mathematical complexity usually seems unobvious, and makes the paper more palatable.

As a referee, I have sometimes asked for a substantive revision of a complex paper if I came up with a much simpler version.  For example, I once asked  an 80 page paper to be shortened to around 15 pages, with no loss of content.   But simplifying a paper is, in general, very difficult and is not the task of a referee.  The unfortunate truth is that authors really can increase their odds of publication by making their papers unnecessarily complex.

Congressman Joe Wilson is a liar

September 15, 2009

Joe Wilson managed to go from obscurity to fame by violating the decorum of the Congress.  He was also able to raise a $1 million for his bad behavior.  (So did his opponent in the upcoming primary.)  He is also a liar.

The lie was not his calling Barack Obama a liar.  Wilson apparently believed that Obama was lying when Obama said that his plan would not cover illegal immigrants.  Rather, Wilson was just being stupid and ignorant given that Obama’s statement was largely true, as reported by factcheck.org.  (One can quibble with Obama’s statement, but that hardly makes Obama a liar.)

Wilson’s lie was when he claimed “[I] let my emotions get the best of me on the critical issue of health care.”  To be honest, I can’t prove that Wilson was lying.  I just believe it to be true.  Conceivably, Joe Wilson has the impulse-control of a 4 year old, and shouted out his insult to the President in one of the most inappropriate venues imaginable just because he could not control himself. I doubt that this is the case.  More likely, Wilson planned to shout out that Obama was a liar, and was just waiting for a moment to do so.  What Wilson did not know was (1) his behavior was uncivil, boorish, and totally unacceptable, and (2) his behavior would be rewarded anyway.   It’s a very sad commentary on our politics that so many are quick to defend such bad behavior.

Japan’s prominent O.R. Ph.D.

September 4, 2009

As reported in the INFORMS news, the current prime minister of Japan, Yukio Hatoyama,  completed his Ph.D. in Operations Research at Stanford in 1976.   He worked under the supervision of Gerald Lieberman on markov repair models.   His 1977 paper

“Markov maintenance models with control of queue”, Journal of Operations Research Society in Japan 20, 164-181

is available online.

He also co-authored a 1984 book entitled “Stochastic models in reliability theory”.

We all hope that the prime minister is successful in repairing the Japanese economy in a reliable manner.

By the way, I started my Ph.D. at Stanford in the semester after Dr. Hatoyama left the department.  So, I never met him, but wish that I had.

Using Operations Research to improve hospital efficiencies

September 1, 2009

There is a great article that promotes the use of Operations Research in hospitals that was printed in the Boston Globe this week.  (Actually, it promotes Operations Management rather than O.R.)  Eugene Litvak of Boston University  has worked with Cincinnati Children’s hospital to improve “patient flow” resulting in a far better utilization of their resources.  Litvak’s improvement was comparable to an increase in 100 hospital beds, which in turn was comparable to a savings of $100 million per year.  The hospital was initially resistant to change, as are most hospitals.  But they are very pleased with the results.

Anyone who has experienced a hospital knows that there are often long waits both by patients and staff.   It is an environment that could use lots of O.R. help.  Dr. Michael Long, one of Litvak’s collaborators, put it well.

In some respects, Eugene [a Russian immigrant] was right at home [in dealing with U.S. hospitals].  It reminded him of the way things are done in Russia.

A revolutionary device for taking notes

July 18, 2009

Recently I heard of a new product called “SmartPen.”  It’s manufactured by LiveScribe.  As far as I can tell, it is a totally revolutionary product for taking notes. You can write notes into a note book and record the audio of what is happening at the same time.  Later, when you click on a word in your written notes, it will replay the audio that was recorded, starting five seconds before the word was written in your notes.  So, if you take notes during a lecture, you can instantly play back any part of the lecture that you want by just clicking on a word.

Here is a detailed blog entry from an MIT undergraduate named Michael Snively.  He writes:  “This pen, hands down, is the most amazing and potentially beneficial note-taking tool I’ve ever seen in my life.”

I haven’t used the product, but plan on buying one for my daughter, who will be starting college this coming fall.

On making games between friends more even

July 17, 2009

Suppose friends of unequal ability play games on a regular basis.  How can one make the games fair?  A classic approach comes from golf.  Each person subtracts his or her handicap from the score.  In principle this evens up the game.

Here is an alternative approach.  Suppose that A plays B and that A is typically 10 strokes better than B.   So, the first game, the discount for player B is set to 10.  That is, B is permitted to subtract 10 from his score.  If B wins the game, the discount is reset to 9.  If A wins, the discount is reset to 11.   In the long run, A and B win approximately the same number of games, regardless of their relative skills.

This strategy applies to any game that is determined by a final score that is played by friends who want to even the odds.