Archive for August, 2006
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Pinyin news » Blog Archive » Festschrift for John DeFrancis now available for free
Pinyin news » Blog Archive » Festschrift for John DeFrancis now available for free
I have mixed feelings about DeFrancis’ work, but this should be a useful resource.
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Digital cameras Tip: Rename your digital photos automatically in Windows XP – Tips, Tricks, and How-tos at CNET.
Digital cameras Tip: Rename your digital photos automatically in Windows XP - Tips, Tricks, and How-tos at CNET.
Unless you really have a lot of time on your hands, I doubt you want to go through the massive folder that contains your European vacation photos and rename them Europe_1.jpg, Europe_2.jpg, and so on down the line. If you’re running Windows XP on your computer, you don’t have to do this. Simply apply this hack to quickly apply a meaningful label to every picture in the folder.- First, open the folder and select View > Thumbnails.
- Click the last picture in the folder you want to rename, hold down the Shift key, and click the first picture; this will select them all.
- Right-click the first photo, and select Rename from the drop-down menu.
Windows XP will highlight the filename for the first photo, enabling you to give it a descriptive name. After you type in the name, click the white space outside of the photo and watch as Windows applies the name with a sequential number to each picture in the folder.
this looks useful
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Good Math, Bad Math : Roman Numerals and Arithmetic
Good Math, Bad Math : Roman Numerals and Arithmetic provides a discussion of doing arithmetic with Roman Numerals.
Back in 1995, David Paredes and I wrote a chapter that discussed this in part,
The Chu-Carroll discussion is generally accurate, although it overlooks an important feature of Roman Numerals that was used in teaching arithmetic. That is the incorporation of addition and subtraction into number representations.
If you want to add IX + XI = XX (9 + 11 = 20), you can see that that IX consists of 10-1 and XI consists of 10+1, so that +1 -1 = 0.
The construction of Roman numerals directly include tens-complements and five-complements. In much of East Asia, tens-complements are taught explicitly in early grades and used in addition above 10.
Thus, if you want to add 9 + 4, you take advantage of knowing that the tens complement of 9 is 1 to turn it into
10 – 1 + 4 = 10 + 3 = 13 (of course, the fact that the name for 13 is “10 3” in Chinese-related systems helps a bit).
It didn’t make it into the final paper, but I remember reading about an approach to mathematics education in England that involved using Roman Numerals for addition and subtraction (because they were seen as conceptually simpler) and then introducing Arabic numerals for multiplication and division (because there aren’t compact algorithms for those operations with Roman Numerals).
The trade-offs between ease of acquisition and ease of use are important ones for any cognitive system. Arabic numerals are very opaque conceptually, but once mastered are a very efficient system for computation.
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Maybe it wasn’t such a serious plot after all
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Latest PowerPoint outrage
Apparently this slide was much of the basis for U.S. post-Saddam planning for Iraq. Sigh. Via Arms & Influence from the book Fiasco by Thomas Ricks.
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Twenty-five years ago, today
Twenty-five years ago, today, IBM announced its first personal computer. I remember that day because I happened to be in Ann Arbor, working with some people here to write a large grant proposal to do some research in China. The proposal wasn’t funded, but I ended up doing the work that I’d planned to do on it, and now I find myself back in Ann Arbor.
At the time, I was in my last year in graduate school and considered buying what passed for a PC as a way of carrying my intellectual world with me (in graduate school, I wrote papers on an old electric Olivetti typewriter my parents gave me when I started college, which had a disturbing tendency of dropping small parts, most of which it seemed to do perfectly well without). I thought about getting the Osborne I portable computer, although it was prohibitively expensive (about a quarter of my grad student salary) and very limited. I’d had experience using systems that worked much like modern PC’s—an IBM 360/44 in college that we operators could use like a PC, and a nice terminal system when I worked as a programmer at IBM, as well as an IBM 5100 that I’d used to learn APL.
I wouldn’t say that PCs were life-changing in the way that the Internet has become—they were much anticipated and in some ways were like electric cars—they won’t do anything that gasoline cars don’t do, but may perhaps be more convenient and less polluting.
The IBM PC was a step toward making knowledge accessible in the way that takes my breath away whenever I stop to think about it.
