Posts

May 22, 2013

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2:57 PM | Research Software Made in Manchester

Earlier this year I was awarded a fellowship from the software sustainability institute, an organization that works to improve all aspects of research software. During their recent collaborations workshop in Oxford, it occurred to me that I was aware of only a relatively tiny number of software projects at my own institution, The University of [...]

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1:27 PM | To Throw Away Data: Plagiarism as a Statistical Crime

I’ve been blogging a lot lately about plagiarism (sorry, Bob!), and one thing that’s been bugging me is, why does it bother me so much. Part of the story is simple: much of my reputation comes from the words I write, so I bristle at any attempt to devalue words. I feel the same way [...]The post To Throw Away Data: Plagiarism as a Statistical Crime appeared first on Statistical Modeling, Causal Inference, and Social Science.

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11:29 AM | Looking for small projects

I’m looking for small consulting projects to fill the gaps between larger projects. I’m available for projects that would take up to a few days. I can’t take on another large project right now. However, if your company takes several…Read more ›

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10:37 AM | Mr. Ratings Reformer Goes to Washington: Some Thoughts on Financial Industry Activism

This is a guest post by Marc Joffe, the principal consultant at Public Sector Credit Solutions, an organization that provides data and analysis related to sovereign and municipal securities. Previously, Joffe was a Senior Director at Moody’s Analytics for more than a decade. Note to readers: for a bit of background on the SEC Credit Ratings […]

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10:00 AM | SAMSI Undergraduate Workshop — Predicting the 2013 Hurricane Season Using Real Data

During the week of May 13, 2013, thirty-four students from around the United States attended the Statistical and Mathematical Sciences Institute (SAMSI) Undergraduate Modeling Workshop. Continue reading →

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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€¦]

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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€¦]

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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 →

May 21, 2013

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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 […]

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8:32 PM | Eben Moglen teaches us how not to be evil when data-mining

This is a guest post by Adam Obeng, a Ph.D. candidate in the Sociology Department at Columbia University. His work encompasses computational social science, social network analysis and sociological theory (basically anything which constitutes an excuse to sit in front of a terminal for unadvisably long periods of time). This post is Copyright Adam Obeng 2013 and licensed under […]

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8:25 PM | Predicting number of landfalls of hurricanes — Undergraduate Modeling Workshop produces forecasts for 2013

Thirty-four undergraduate students from around the U.S. came to SAMSI and NC State University the week of May 13-17. During the week, the students interacted with an atmospheric scientist who works on hurricane research, and applied mathematicians and statisticians who … Continue reading →

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6:44 PM | Never applied for a job

John Conway explained in an interview that he’s never applied for an academic job. I am rather proud of the fact that, in some sense, I never applied for an academic position in my life. What happened: I was walking…Read more ›

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3:14 PM | Helium atom

Required math: calculus Required physics: Schrödinger equation Reference: Griffiths, David J. (2005), Introduction to Quantum Mechanics, 2nd Edition; Pearson Education – Problem 5.9. So far, we’ve looked at identical particles only in the non-interacting case. In real life, of course, most particles interact with each other, so the Schrödinger equation must take this into account. […]

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2:15 PM | Algorithmic view of historicity and separation of scales in biology

A Science publications is one of the best ways to launch your career, especially if it is based on your undergraduate work, part of which you carried out with makeshift equipment in your dorm! That is the story of Thomas M.S. Chang, who in 1956 started experiments (partially carried out in his residence room in […]

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1:53 PM | Recently in the sister blog

The end of Michelle Rhee. The relevance of statisticians to researchers in different fields of social science. Regression discontinuity. Free expression vs. not wanting to make anyone personally uncomfortable. Political coalitions are diverse (and there’s no use pretending otherwise). According to David Brooks, staying out of jail is a conservative value. I’ve heard of the [...]The post Recently in the sister blog appeared first on Statistical Modeling, Causal Inference, and Social Science.

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12:04 PM | Is the Economy Saving Obama’s Approval Ratings?

Political coverage over the last week has focused on a series of stories that reflect negatively on the executive branch, but President Obama's approval ratings have held steady.

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12:00 PM | The rise and fall of binomial coefficients

When you expand (x + y)n, the coefficients increase then decrease. The largest coefficient is in the middle if n is even; it’s the two in the middle if n is odd. For example, the coefficients for (1 + x)4…Read more ›

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8:42 AM | Travelling salesman-based compressive sampling

The issue of random sampling in compressive sensing was made more clear, in my view, by the work of Ben Adcock and Anders Hansen ( see A Q&A with Ben Adcock and Anders Hansen: Infinite Dimensional Compressive Sensing, Generalized Sampling, Wavelet Crimes, Safe Zones and the Incoherence Barrier. ). In short, the whole random sampling story has some problems at low frequencies. In MRI, the field at the leading edge of compressive sensing, several sampling techniques have been evaluated to [â€¦]

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7:17 AM | Geometry, Imaging and Computing

Geometry, Imaging and Computing A short note to myself: There is the new journal “Geometry, Imaging and Computing” published by International Press which looks interesting for papers inbetween computer vision and computer graphics. Filed under: Uncategorized

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12:02 AM | Cheap fountain pen comparison

For the past few years I've been carrying around a small notebook to jot down notes from talks, research ideas, expenses, etc. (I guess I could do it on my phone but I prefer pen and paper.) I like writing with fountain pens, but don't care to carry around an expensive one: I don't feel I need to impress people with how much I spend on accessories, and I don't want to worry about losing it. I had been using disposable Pilot Varsity pens, but occasionally (especially if I took them on airplanes) [â€¦]

May 20, 2013

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9:44 PM | Perihelion shift: numerical solution

Reference: Moore, Thomas A., A General Relativity Workbook, University Science Books (2013) – Chapter 11; Problem 11.11. The general case of an object orbiting a much larger mass is treated by the equations for radius and angle as functions of proper time: Taking the derivative of the first equation with respect to and cancelling off […]

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9:00 PM | Course final projects

The course is now concluded, the grades are entered. The final activity of the semester was the final project presentations day, when 16 student teams presented the results of the 10-week class final project. The breadth of topics for the final projects was impressive and was made possible in part by over 15 class partners [...]

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6:56 PM | What is mathematical research ?

What is mathematical research? And how is it done? Questions that have been on my mind for very long. We know what researchers do:- answering questions asked in the literature;- discovering a new theorem;- publishing an article in the Journal for Number Theory;- writing a book;- lecturing about their work and giving talks;- being part of a research community.Researchers are either employed by a university or by a corporation. University researchers have a commitment to teach and corporate [â€¦]

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2:42 PM | Blog moved over...

In case anyone is (still) reading this blog, I've absorbed it into my other website. I'll maintain this site as a (static) professional consulting website, but the blog now lives at www.chadtopaz.com/blog Thanks!

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1:29 PM | Elements of Statistical Learning

Although the book is available as PDF file from http://www-stat.stanford.edu/~tibs/ElemStatLearn/ I decided to spend the $80 and ordered the book as real book. It was delivered this weekend. Some beautiful graphs and pictures: highly recommended.

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1:18 PM | Evaluating Columbia University’s Frontiers of Science course

Frontiers of Science is a course offered as part of Columbia University’s Core Curriculum. The course is controversial, with some people praising its overview of several areas of science, and others feeling that a more traditional set of introductory science courses would do the job better. Last month, the faculty in charge of the course [...]The post Evaluating Columbia University’s Frontiers of Science course appeared first on Statistical Modeling, Causal Inference, and Social [â€¦]

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1:14 PM | things I found in my office while packing

I found a number of things in my office while packing up for UW-Madison. I officially move later this week. The Onion article is entitled “Mead Releases New Grad-School-Ruled Notebook:” “We here at Mead understand that as students get older and wiser, they need notebooks with increasingly narrow lines,” Mead CEO John A. Luke told reporters. […]

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1:04 PM | What happened that the journal Psychological Science published a paper with no identifiable strengths?

The other day we discussed that paper on ovulation and voting (you may recall that the authors reported a scattered bunch of comparisons, significance tests, and p-values, and I recommended that they would’ve done better to simply report complete summaries of their data, so that readers could see the comparisons of interest in full context), [...]The post What happened that the journal Psychological Science published a paper with no identifiable strengths? appeared first on Statistical [â€¦]

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11:50 AM | Need a 12-digit prime?

You may have seen the joke “Enter any 12-digit prime number to continue.” I’ve seen it floating around as the punchline in several contexts. So what do you do if you need a 12-digit prime? Here’s how to find the…Read more ›

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11:03 AM | Money, food, and the local

I take the Economist into the bath with me on the weekend when I have time. It’s relaxing for whatever reason, even when it’s describing horrible things or when I disagree with it. I appreciate the Economist for at least discussing many of the issues I care about. Last night I came across this book […]

May 22, 2013

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