Day 4 (June 17, 2010)

As a statistician you are always looking for patterns and making things predictable. I have been beating my head against the wall for the past 3 days trying to see if the current time prediction process is working and my conclusion is that the data is so haphazard given the known inputs that making a reasonable prediction is unrealistic. I feel a little better about things at this point because I was told that is an okay conclusion. That is the conclusion my coordinator was expecting actually. Whew, what a relief! I am going to turn my attention to trying to create a more reliable predictor.

Some terminology that is part of this industry can easily be tied to my AP Stat class. One of the significant features of statistics is to look at the normal curve. Part of the normal curve is the 68-95-99.7 concept. That is, 68% of the data is within 1 standard deviation (sometimes referred to as within 1 sigma - the Greek symbol commonly used to represent standard deviation), 95% is with 2 standard deviations (2 sigmas), and 99.7% is within 3 standard deviations (3 sigmas). The industry term that applies here is "6 sigma". 99.9999997% of all the data is within 6 standard deviations from the mean. In other words, it is nearly impossible for the data not to fit within that parameter. It makes me feel pretty good about getting into the airplane the next time I need to travel because Rockwell Collins supplies circuit boards for those planes.

I ran into a former student's father today and he wanted to show me what he is working on. He is testing a flight simulator. He has to make sure the simulator works for every possible combination of settings. He has already spent 4 months going through the documentation and was only about 3/4 of the way through the about 400 page binder. He has several tags on the pages indication he needs someone else to look at portion as he was not able to verify that it worked. It sounds like very tedious work, but he does get to play on a flight simulator all day.

I attended a presentation on Circuit Board production today. It was specifically about the industry regulation-led change on the type of solder used to hold components in place on the circuit boards. There is a shift from tin-lead solder to lead-free solder. The new type solder itself apparently works almost as well as the previous with the exception that the lead-free solder tends to grow "tin-whiskers". These tin whiskers cause many electrical issues if they touch other metal portions of the board or casing. Another problem with the lead-free solder is the solder gun must be set at a higher temperature to melt it so the manufacturer can get the solder in place. This can cause overheating problems for the components or even the board if they are not adjusted to be able to withstand the higher temperature.