December 2022 M T W T F S S 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
© Mark Biegert and Math Encounters, 2022. Publication of this material without express and written permission from this blog’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to Mark Biegert and Math Encounters with appropriate and specific direction to the original content.
DisclaimerAll content provided on the mathscinotes.com blog is for informational purposes only. The owner of this blog makes no representations as to the accuracy or completeness of any information on this site or found by following any link on this site. The owner of mathscinotes.com will not be liable for any errors or omissions in this information nor for the availability of this information. The owner will not be liable for any losses, injuries, or damages from the display or use of this information.
Author Archives: mathscinotes
During a major storm two weeks ago with 80 mile per hour winds (129 kph) and heavy rain, a lightning strike near my garage destroyed two TVs, a power adapter for my robot lawnmowers, a wireless router, two data switches, and my furnace's propane tank regulator and copper feedline. As an illustration of the damage, Figure 1 shows the residue left from my mower power adapter exploding. The light region inside the smudge is from my fingers wiping across the smudge to see how thick the film was. The film was removed using mineral spirits. A small burn mark is all that remains. Continue reading
I use Python or R for my large-scale data work, but I do find Excel a very powerful ad hoc data analysis tool, particularly with some of the new functions that use spillable ranges. Today, I was given a large table of Engineering Change Orders (ECOs) and a comma-separated list of the documents each ECO affected (very abbreviated form shown in Figure 1). Continue reading
Quote of the Day Great things are not done by impulse, but by a series of small things brought together. — Vincent van Gogh Introduction I recently went into a home center and was shocked to see a 2‑in x … Continue reading
A number of people have asked questions about the process we used to design and build our cabin in northern Minnesota (Figure 1), a build that I have discussed in other posts (link, link). The questions center on the tools we used, what the build process was like, and things to watch for. The following post examines our design and build process from the standpoint of what went well and not so well. Continue reading
I recently had a situation where I needed to correct a number of date/time values because they did not take into account Daylight Saving Time (DST). To be specific, some transactions from China were recorded assuming a fixed time offset with respect to US Central Standard Time. Because of DST, this is not always the case. My customer only works in Excel, so the work was done in Excel. Continue reading
I was watching a documentary on the Battle Off Samar on my favorite Youtube naval channel called Drachinifel. During this show, Drachinifel stated that the battleship Yamato displaced more tonnage than the entire Task Group 77.4.3 (call sign Taffy 3) defense force. I found this a remarkable statement and one that I could verify using a little bit of web scraping. Because one of the students I tutor use R, I thought this would be a good exercise to implement using R and Rmarkdown (a great report generation tool). Continue reading
In this post, I will examine the fuel consumption of the three most modern battleship classes that the US deployed during WW2: South Dakota, North Carolina, and Iowa classes. The data is scraped from the Hyperwar website, which is one of my favorite targets for data extraction. In this case, the Hyperwar page contains a set of tables from the US Navy document FTP 218: War Service Fuel Consumption of US Navy Surface Vessels. Continue reading
This post is going to look at the Destroyers for Bases deal between the US and UK. The bargain was an executive agreement announced on 2-Sep-1940 to trade 50 WW1-era US destroyers to the UK for US basing rights in the Caribbean, Bermuda, and Newfoundland. I have seen the destroyers described as obsolete, which seemed odd for ~20-year-old destroyers that nominally have 30 year lifetime (typical for most US Navy ships). Continue reading
A number of years ago, I was asked by a father to assist him and his son with a science project that involved calculating the ballistic coefficient of a BB gun projectile. I provide dthis father-son duo with the required calculations (documented here) and the answer I obtained seemed reasonable. Continue reading