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David Joyner
Works at USNA
Attended Georgia Institute of Technology
Lives in arnold, md
8,342 followers|550,397 views
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David Joyner

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Photos from a trip to Philly.
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Nice mate-in-2 from 1911, thanks to the futilitycloset.com:
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Just saw this nice new blog on math education.
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Very easy mate-in-2 due to Sam Loyd, thanks to futilitycloset.com:
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David Joyner

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Huang's tagline is "Speculative fiction writer. Mathematician. Gunslinger."
What more do you want?
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Interesting study on standing vs sitting while working.
Replacing 2 hours of sitting a day with 2 hours of standing or stepping may be good for your heart and even your waistline.
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I've had a standing desk for several years at home now, and at one of my workplaces, but I haven't noticed a lessening of my waistline. Definitely helped the back pain though.
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Interesting copyright news
Attorneys for suing filmmakers uncover a blurry version of an 88-year-old book in the files of Warner/Chappell. That leads to another serendipitous discovery.
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Very simple card trick, thanks to futilitycloset.com.

"Arrange cards with values ace through 9 in a row, in counting order, with the ace on the left.
Take up a card from one end of the row — left or right, your choice.
Do this twice more, each time taking up the leftmost or the rightmost card in the remaining row.
When you have three cards, add their values and divide the total by six. Count the cards that remain on the table from left to right.
The card in the nth position will be the 4."

Is there is a generalization to other numbers of cards?

source: http://www.futilitycloset.com/2015/07/16/destiny-2/
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+Joal Heagney Cool, thanks!
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Nice short intro to the combinatorial Kirkman schoolgirl problem, care of the futilitycloset.com:
“Fifteen young ladies in a school walk out three abreast for seven days in succession: it is required to arrange them daily, so that no two shall walk twice abreast.” The Rev. Thomas Penyngton Kirkman posed this query innocently in The Lady’s and Gentleman’s Diary in 1850. It’s trickier than it looks — though seven …
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Just saw this one-liner: Time flies like an arrow; fruit flies like a banana.
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That's a really old one that came up a lot back in the heyday of artifical intelligence work. How could a software program parse that?
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Have him in circles
8,342 people
Marcelene Ellington's profile photo
Raphael Magalhães's profile photo
Ngoc Nam Tran's profile photo
‫سعيد سهرابي‬‎'s profile photo
elias moh's profile photo
Fiber Follies's profile photo
Andrew Kornblatt's profile photo
Carsten Ritter's profile photo
shogun x's profile photo
Education
  • Georgia Institute of Technology
    math
  • University of Maryland, College Park
    math
Basic Information
Gender
Male
Story
Tagline
math, writing, tech, edu, ...
Introduction
Enjoy tinkering with mathematics, writing, Sage (www.sagemath.org), video, chess, and photography. Interested in math education-related and open-source software issues.
Bragging rights
have managed to stay off facebook
Work
Occupation
math prof
Employment
  • USNA
    math prof, present
Places
Map of the places this user has livedMap of the places this user has livedMap of the places this user has lived
Currently
arnold, md
Previously
mountain view, ca - kent, wa - decatur, ga - princeton, nj - san diego, ca
Links
I have used All for the Pet for years and never once had rude service. The store doesn't even open until 9am and Lisa often comes in early to help out people who want to drop off their pet before going to work. I think she does a good job with my pets and her prices are reasonable.
Public - 2 years ago
reviewed 2 years ago
1 review
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