Posts

May 31, 2013

5:00 AM | Simulated Cicadas Favor Prime Number Emergence Cycles

Researchers from Brazil's Universidade Estadual de Campinas used a computer simulation to confirm paleontologist Stephen J. Gould's prediction that it is evolutionarily advantageous for cicadas to emerge at intervals lasting a prime number of years.

May 22, 2013

5:01 AM | Put your money where your mouth is: personal finance advice

Pound Foolish by Helaine Olen is an excellent exposé of the personal finance industry. After reading it, you’ll never look at a talking head on TV the same way. It seems many personal finance advisors have an attitude of “Do what I say, not what I do.” Here are a few examples from the book. [...]

5:01 AM | Good and Bad Decisions (5-22-13)

Bad decisions 1. JC Penny uses fake regular prices so sales look better 2. If you’re not a pure-math person or an expert programmer, that’s all right, because you can be on a team with people who are” 3. Thinking everything at Subway is healthy 4. Replacing expensive habits with slightly less expensive ones 5. [...]

5:01 AM | PalBOMP/PolBOMP: Compressive Parameter Estimation for Sparse Translation-Invariant Signals Using Polar Interpolation - implementation -

Karsten Fyhn just let me know of their recent article and attendant code repository. Compressive Parameter Estimation for Sparse Translation-Invariant Signals Using Polar Interpolation by Karsten Fyhn, Marco F. Duarte and Søren H. Jensen We propose new compressive parameter estimation algorithms that make use of polar interpolation to improve the estimator precision. Moreover, we evaluate six algorithms for estimation of parameters in sparse translation-invariant [â€¦]

4:53 AM | A smart post from Felix Salmon

Felix Salmon:My point here is that technology has a tendency to create its own norms. The classic example is the automobile — a technology which kills more than 30,000 Americans every year. From the 1930s through the 1990s, societal norms about who roads belonged to, and what people should do on them, were turned on their head thanks to the new technology. The dangerous new activity allowed by the new technology became the privileged norm, to the point at which just about all other road-based [â€¦]

4:00 AM | Math Inspired Furniture Debuts during Milan Design Week

In designing his 'f3' collection of rotomolded furniture, Fabio Novembre adhered to the principle of 'form follows function' and derived the shapes of the pieces from mathematical surfaces.

3:59 AM | Improved Presentations with Two Lessons from Tufte

Having spent time in the Air Force and then developing software as a government contractor, I’ve survived more than my share of bad presentations. During this time I began reading the works of the statistician Edward Tufte[wiki]. I’d like to … Continue reading →

3:01 AM | Matt Parker Explains Math Jokes

I’ve learned one thing in my life — the least funny math jokes are the ones you have to explain. As E. B. White said, Humor can be dissected as a frog can, but the thing dies in the process, and the innards are discouraging to any but the pure scientific mind. Matt Parker, who did […]

2:15 AM | Intersections, a high school math-science journal

At the end of last year, a science teacher and I came up with the idea of creating a math-science journal for students to publish their work in. Our school has a literary and art journal and even a foreign language journal. But there is no forum for students to show off their more mathysciency […]

2:02 AM | On This Very Page...........

Many a time less is more, hence I shall keep the introductions realshort and sweet.WELCOME."Everything should be made as simple as possible, but not simpler."-Albert Einstein

2:01 AM | Problem 24: Solving For Brightest Point On Sphere (Phone Illumination Model)

CLICK ON IMAGE TO ENLARGE

1:42 AM | How kids think about multiplying polynomials

The kids are confident I recently gave my students another survey. At the time of the survey, the students had just studied exponents and were about to begin multiplying/factoring polynomials. To emphasize: they've never studied multiplying/factoring in a formal setting. The second half of this survey is what you folks call a pre-assessment or something. This response from a student -- let's call him Mike -- is especially interesting. Mike nails the first three questions. A [â€¦]

1:38 AM | Diving into the Multiplying Polynomials Survey

This is from yesterday’s survey, which was discussed over at this post. What do you make of the responses, particularly the differences between (2a+6) in the first response, and (2x+49) in the second?

1:34 AM | More Depressing Evidence of Modularity

Christ, it's depressing how smart one can be in one area while believing the most transparently idiotic things in others (especially when moral culpability is involved). Read THIS COLUMN ("MOOC Professors Claim No Responsibility for How Courses Are Used") for yet more evidence concerning the correctness of John Calvin on...

1:10 AM | Problem of the Day 3 – Forming Numbers

Using 1, 2, and 3, how many numbers can be formed if repetition is not allowed?

1:10 AM | Twin Primes Are Useful

Why the recent breakthrough is important Yitang Zhang, of the University of New Hampshire, has apparently proved a finite approximation to the famous Twin Prime Conjecture. This is a result of the first order. After ten days of progressively more detailed news, including today’s article in the New York Times, Zhang’s 56-page preprint has just […]

12:30 AM | Multiple recurrence and convergence results associated to $\F_{p}^{\omega}$-actions

Vitaly Bergelson, Tamar Ziegler, and I have just uploaded to the arXiv our joint paper “Multiple recurrence and convergence results associated to -actions“. This paper is primarily concerned with limit formulae in the theory of multiple recurrence in ergodic theory. Perhaps the most basic formula of this type is the mean ergodic theorem, which (among […]

12:19 AM | All My Lessons

(and assessments). Yeah, it’s the end of my 2nd year of teaching Precalculus, Physics, and Chemistry, and I figure I should be able to post my lessons without too much shame. Actually, I am embarrassed of some things, because I’d like to … Continue reading →

12:10 AM | An Unheralded Breakthrough: The Rosetta Stone of Mathematics

An Unheralded Breakthrough: The Rosetta Stone of Mathematics: Edward Frenkel: Deligne’s most spectacular results are on the interface of two areas of mathematics: number theory and geometry. At first glance, the two subjects appear to be light-years apart. As the name suggests, number theory is the study of numbers, such as the familiar natural numbers (1, 2, 3, and so on) and fractions, or more exotic ones, such as the square root of two. Geometry, on the other hand, studies shapes, such as [â€¦]

12:08 AM | The Gram-Schmidt Process and Orthogonal Vectors

Suppose I gave you some red fingerpaint and asked you to make all the colors you could from this paint. You’d probably come up with a diverse collection of pinks, reds and burgendys – going through the range of reds … Continue reading →

12:00 AM | On This Day in Math - May 22

The Le Petit Journal cover, on 1912 April 21, shows eclipse watchers in 1912 along with the solar eclipse of May 22, 1724, the previous total solar eclipse visible from Paris, France *Wik“Biographical history, as taught in our public schools, is still largely a history of boneheads:ridiculous kings and queens, paranoid political leaders, compulsive voyagers, ignorant generals - the flotsam and jetsam of historical currents. The men who radically altered history, the great [â€¦]

May 21, 2013

10:47 PM | “Simple product”, a new kind of product of funcoids

Today I’ve discovered a new kind of product of funcoids which I call “simple product”. It is defined by the formulas: and . Please read my book.

10:13 PM | inference in Kingman’s coalescent with pMCMC

As I was checking the recent stat postings on arXiv, I noticed the paper by Chen and Xie entitled inference in Kingman’s coalescent with pMCMC. (And surprisingly deposited in the machine learning subdomain.) The authors compare a pMCMC implementation for Kingman’s coalescent with importance sampling (à la Stephens & Donnelly), regular MCMC and SMC. The […]

9:48 PM | Intractable Problems — Part One: Set Problems

My professor and advisor Dr. Alice McRae provided a list of intractable problems for us to ponder in our genetic algorithms class, and I thought I would expand on some of them here for reference. All of these problems are intractable, which means that they are very, very difficult to solve precisely with a computer. Most of […]

9:36 PM | Películas de jabón y superficies mínimas

Esta entrada participa en la Edición 4.1231 del Carnaval de Matemáticas cuyo anfitrión es el blog Matemáticas interactivas y manipulativas. Video donde se comprueba que con una solución jabonosa podemos visualizar los problemas de Recorridos Mínimos y Superficies Mínimas que en muchas ocasiones matemáticamente son difíciles de calcular y visualizar. Explicaciones en el siguiente fichero Superficies_m_nimas.pdf

9:34 PM | Ακρότατα στην γεωμετρία

ΠΑΤΗΣΕ ΕΔΩ

9:23 PM | Raspberry Pi Setup

I am setting up a second Raspberry Pi … decided this time to log all the update and installation steps for later use. A. Setting up the operating system on an SD card Download a disk image from raspberrypi.org. Whatever method you use, you should end up with a file ending in .img. This is […]

9:19 PM | Math Games with a Deck of Cards

Summer learning is so critical, especially for students who are already struggling. I've been working with a peer tutoring group this year (5th graders tutoring 3rd graders), and I wanted to give them a gift for completing the program. I bought each of the students a deck of cards, and my idea was to create a booklet to give them containing instructions for easy math games they could play using the cards. In scouring the Internet for ideas, I came across the website of an [â€¦]

9:16 PM | 9 Equations True Geeks Should (at Least Pretend to) Know

http://www.wired.com/wiredscience/2011/11/equations-for-geeks/?pid=2356

9:00 PM | Two new proofs in number theory

In grade school we learn how to divide one whole number by another. Sometimes nothing is left over, but often the division leaves a “remainder”. One learns to say things like “Eleven divided by five is two remainder one”. Numbers that always leave a remainder when divided by another number...

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