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Author Archives: mathscinotes
Most of my naval history reading has been about the Pacific War. This means I have not read much about the Battle of the Mediterranean. I recently heard a historian (Drach) say that the UK lost 135 major warships in the Mediterranean Theater during WW2. I must admit that I was surprised at the high losses and decided to investigate further. This theater saw numerous major battles (examples like Taranto, Cape Matapan) and some real technology innovations (example in Figure 1). Continue reading
This post uses a combination of data from a Github repo by Jeffery Arnold that contains a fantastic amount of Civil War battle data and some Wikipedia scraping to generate similar tables. I should note that my casualty results are significantly different than Bonekemper’s because there are large differences between sources of Civil War casualty data. The reasons behind these differences are complex, but the Arnold repo has data from a number of sources. I chose his Wikipedia file because it is easy to check where the data came from. Continue reading
I am a huge fan of Drachinifel’s naval history channel. The other day, Drach was participating in the Armchair Admiral’s program, during which he presented two charts on the Battle of the Atlantic that I have never seen before: (1) A chart of tonnage sunk by U-boats versus time and (2) a chart of U-boats sunk versus time. The unique aspect of the charts was that the data points were colored based on whether the Enigma cipher was broken at the time and whether centimetric (microwave) radar was deployed. These charts really got me thinking about the impact of technology on the struggle against U-boats. Continue reading
I recently needed to generate a table that showed how every user requirement generated by our Marketing Department was mapped to one or more system requirements. This table is known as a flowdown table. For all sorts of reasons, none of them good, our requirements database could not generate the report. I decided that Excel would be the appropriate tool to generate the table we required. I should note that a Python version was also developed and will likely be used in the future. Continue reading
Quote of the Day Asking for help isn’t giving up, it is refusing to give up. — Charlie Mackesy I have been reading a couple of books about Admiral Chester Nimitz and his conduct of the Pacific War during WW2. … Continue reading
I just finished watching a series of videos on the Guadalcanal Campaign by Drachinifel, whose work is superb (Figure 2). The marines derisively referred to this campaign as Operation Shoestring because of the resource limitations. Things were no better for the sailors. Unlike many WW2 island campaigns, more sailors died in the battles than ground troops (link). The Allies, and in particular the US Navy (USN), had to learn the hard way that the Imperial Japanese Navy (IJN) was a force that deserved respect. Many Allied ships were sunk while learning this lesson. Continue reading
My reading and watching lectures on Mahan have motivated me to look at how the US Navy grew and shrank over the years. Fortunately, the Naval History and Heritage Command (NHHC) have an excellent page on the size of the US Navy over time. Unfortunately, the data is scattered throughout the page and it must be scrapped so that I can consolidate and graph it. This post is about using Power Query to scrape the data from the page and generate a graph in Excel of the number of active ships in the US Navy over time. Continue reading
Two weeks ago, the grass around my garage looked pretty scraggly and weed-infested, so I decided it was time for fertilizer and weed-killer. I am not very knowledgeable about lawns and lawn care, so I decided to research online. This research is summarized in this post. Yes, it was time for some fertilizer and weed-killer. Continue reading
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