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David Joyner
Works at USNA
Attended Georgia Institute of Technology
Lives in arnold, md
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David Joyner

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An interesting, very simple to state unsolved problem on finite sets, care of the futilitycloset.com. I'd not heard of this one before.
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There is currently a polymath project for this conjecture: http://polymathprojects.org/2016/02/07/polymath-11-is-now-open/
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I loved this mate-in-2 from the futilitycloset.com. I considered the winning move and still didn't see the mate, so rejected it! Very clever. 

(Richard Steinweg, 1860-1943, was a German chess problem composer. According to http://jornalheiros.blogspot.com/2016/01/xadrez-mate-em-2-richard-steinweg.html, this problem goes back to 1893.)
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Thanks! I didn't remember draw was a possible outcome...
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There's an interesting generalization of the Pythagorean Theorem that I'd never heard of. There's a mention of De Gua's Theorem (the 3-dimensional generalization of the PT) on futilitycloset.com, but the wikipedia article https://en.wikipedia.org/wiki/De_Gua%27s_theorem discusses the more general version in n-dimensions. 
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Interesting primality test due to Mann and Shanks which is based on Pascal's triangle, thanks to the futilitycloset.com:
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Interesting way to visualize Shakespeare.
Digital humanities, Data visualization, Network analysis
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Maybe I'm getting stupid in my old age but this mate in 2, care of the futilitycloset.com, completely stumped me.
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i stopped two addictions sometime between 87 and 88. first was smoking cigarettes and the second playing chess. :-)
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David Joyner

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Excellent article on the history of jokes in the US.
From the Marx Brothers to <i>​The Simpsons​</i>, Richard Pryor to Amy Schumer: 100 bits, sketches, and one-liners that changed humor forever.
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From insidehighered.com: Note the question "are these evaluations, commonly referred to as SET, so bad that they’re actually better at gauging students’ gender bias and grade expectations than they are at measuring teaching effectiveness?"
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Funny teaching cartoons from mathwithbaddrawings.com:
Or is it, "metaphors for unfortunate teaching"?
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A train passing by MICA today in Baltimore.
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That looks like a tram.
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Sin of Harold Diddlebock review
The Sin of Harold Diddlebock (also released as "Mad Wednesday") is a 1947 film written and directed by the great Preston Sturges. It starred Harold Lloyd, Jimmy Conlin and (in a small but important role) Frances Ramsden. Plot Summary: A madcap comedy follow...
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Cool geometry fact, care of futilitycloset.com.

I wonder if it was rewritten x = z - y, and if the circles were of different sizes, if the generalization x = a(y-z) holds, where a is the ratio of the radii?
If two unit circles are tangent externally as shown, and from a point P on one circle rays PQ and PR are drawn intersecting both circles, then arc lengths x + y = z. From Claudi Alsina and Roger B. Nelsen, Icons of Mathematics, 2011.
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yes, been planning to, but not getting any time to get around it. i like the sage platform.
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Occupation
math prof
Employment
  • USNA
    math prof, present
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Currently
arnold, md
Previously
mountain view, ca - kent, wa - decatur, ga - princeton, nj - san diego, ca
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
Education
  • Georgia Institute of Technology
    math
  • University of Maryland, College Park
    math
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Male
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.
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