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Posts

March 26, 2015

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1:42 PM | Prize Announcements
John Nash will receive the 2015 Abel Prize (the most prestigious prize in mathematics besides the Fields Medal). The Norwegian Academy of Sciences and Letters is awarding the prize not for Nash’s work on game theory, but for his (and Louis Nirenberg’s) “striking and seminal contributions to the theory of nonlinear partial differential equations and […]
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1:04 PM | Another disgraced primatologist . . . this time featuring “sympathetic dentists”
Shravan Vasishth points us to this news item from Luke Harding, “History of modern man unravels as German scholar is exposed as fraud”: Other details of the professor’s life also appeared to crumble under scrutiny. Before he disappeared from the university’s campus last year, Prof Protsch told his students he had examined Hitler’s and Eva […] The post Another disgraced primatologist . . . this time featuring “sympathetic dentists” appeared first […]
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1:00 PM | For some reason, this morning I found myself thinking about scams and hoaxes involving space exploration
That lead me inevitably to this New York Sun headline from 1835GREAT ASTRONOMICAL DISCOVERIESLATELY MADEBY SIR JOHN HERSCHEL, L.L.D. F.R.S. &c.At the Cape of Good Hope[From Supplement to the Edinburgh Journal of Science]From Wikipedia:The articles described fantastic animals on the Moon, including bison, goats, unicorns, bipedal tail-less beavers and bat-like winged humanoids ("Vespertilio-homo") who built temples. There were trees, oceans and beaches. These discoveries were supposedly made […]
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12:30 PM | Clinical trials and machine learning
Arguments over the difference between statistics and machine learning are often pointless. There is a huge overlap between the two approaches to analyzing data, sometimes obscured by differences in vocabulary. However, there is one distinction that is helpful. Statistics aims to build accurate models of phenomena, implicitly leaving the exploitation of these models to others. Machine learning aims to solve […]
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11:44 AM | Talking tomorrow evening at American University
Tomorrow I’m running down to D.C. after recording my Slate podcast. I’ll be giving an evening talk to the math and statistics folks (and the general public) at American University on Weapons of Math Destruction. So basically the nerdy low-down on what I’m writing about in my book. Here’s the poster (for live links, go […]
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6:21 AM | Mike the Mad Biologist has a good post on tenure
I don't have time to discuss it now, but if you're following the discussion, you should check it out.
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5:00 AM | Real-time Dynamic MRI Reconstruction using Stacked Denoising Autoencoder
Great convergence, here we come ! From the paper:The dataset contains about 17424 volumes; and multiple slices in each volume. In total we have used about 100,000 images for training the SDAE's...Unfortunately, for these datasets, the fully sampled k-space scans are not available. Therefore the reconstruction results obtained from [8] is taken as the basis images for comparison.Using time dependent images reconstructed from some unknown algorithm and comparing it with the temporal […]
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12:28 AM | Understanding Ebola
From the BBC, Hans Rosling on the Ebola epidemic (That’s a diagram of the data collection system behind him) (via Harkanwal Singh)

March 25, 2015

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8:50 PM | Submarine Fiber-Optic Cable Trivia
I am at the Optical Fiber Conference in Los Angeles this week and learning a lot. This morning I attended a great talk submarine fiber optic cables given by Neal Bergano, CTO of TE Connectivity Subcom. I thought I would put my notes on blog for others to view. I was not able to find a copy of Neal's presentation, so I will replicate my notes on his presentation here. Where possible, I will include supporting information that I located on the web. Any errors introduced are mine. Continue reading […]
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8:50 PM | Schaefer's Boolean Formula Games
For a few years (okay, okay, like, 5 years) I've been working on a paper about boolean formula games.  These are games that include a formula involving some boolean variables.  A turn consists of either assigning a value to an unassigned variable or flipping the value of a variable (depending on the game).The canonical problem in PSPACE is QBF, which can be phrased as the following game.  There is a boolean formula in terms of some variables x0 through xn-1.  The first […]
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5:54 PM | MFM2P - Day 31 (Spaghetti Bridges, day 2)
Today's warm up was this visual pattern:I explicitly asked them to colour in how they saw the pattern growing. So many of my students just count the blocks and don't even look at the pattern itself that I felt that I needed to make sure the connection is being made. Here is where we went with it:I love how this is like a little spiral within the cycle as we talk about rate of change/slope and y-intercept every week, even if our focus at the time is not linear relationships. There is also the […]
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4:00 PM | Claude Levi-Strauss (4) vs. Ed Wood (3); Cervantes wins
For yesterday we have a tough call, having to decide between two much-loved philosophical writers, as Jonathan put it in comments: Camus on ramdomness; how make a model when there is no signal — only noise. Cervantes on making the world fit the model through self-delusion. Two fascinating statistics lectures with the same underlying theme […] The post Claude Levi-Strauss (4) vs. Ed Wood (3); Cervantes wins appeared first on Statistical Modeling, Causal Inference, and Social Science.
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2:30 PM | Sensationalist promotion by the World Cancer Research Fund
Today the Daily Telegraph featured the powerful headline "Just three alcoholic drinks a day can cause liver cancer, warns new study" , based on a press release from the World Cancer Research Fund headed “Three alcoholic drinks a day can cause liver cancer, new research finds”.
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1:30 PM | NASDAQ 100 Couples
Heaven, I’m in heaven, and my heart beats so that I can hardly speak, and I seem to find the happiness I seek, when we’re out together dancing cheek to cheek (Cheek To Cheek, Irving Berlin) There are about 6.500 available packages in CRAN repository. If I were a superhuman, able to learn one package … Continue reading NASDAQ 100 Couples →
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1:02 PM | Define first, prove later
This post by John Cook features a quote form a book “Calculus on Manifolds,” by Michael Spivak which I think was the textbook for a course I took in college where we learned how to prove Stokes’s theorem, which is something in multivariable calculus involving the divergence and that thing that you get where you […] The post Define first, prove later appeared first on Statistical Modeling, Causal Inference, and Social Science.
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1:00 PM | At this point, the only things Mars One is likely to get into orbit are the wheels coming off of the bus
More background on the Mars One story.From CTV News:The Dutch non-profit group behind the project recently announced that it was pushing back the planned launch to 2027, due to a lack of funds for a robotic mission that was scheduled to precede the first human launch. The aim of the robotic mission is to test out the technologies required for human survival on Mars.From NBC:The Dutch-based Mars One venture is closing in on choosing its crews for one-way trips to the Red Planet, but will they be […]
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1:00 PM | Bayesian survival analysis for "Game of Thrones"
Last fall I taught an introduction to Bayesian statistics at Olin College.  My students worked on some excellent projects, and I invited them to write up their results as guest articles for this blog.One of the teams applied Bayesian survival analysis to the characters in A Song of Ice and Fire, the book series by George R. R. Martin.  Using data from the first 5 books, they generate predictions for which characters are likely to survive and which might die in the forthcoming books. […]
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12:55 PM | Oligopolistic producer behavior or why airline tickets are not cheaper
  Small example from the literature:   We implement different behaviors with a GAMS model: Behavior Equations Oligopolistic (MCP) Nash-Cournot Equilibrium Monopolistic (NLP) Think of this as firms are merged. Competitive (NLP) Technique: Optimize Social Welfare Objective. Check solution […]
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11:36 AM | I felt warm and relaxed
When I was a kid, being the child of nerd atheists, I spent more time watching Star Trek, Animal House, and Monty Python than in church. Scratch that, I spent no time at all in church, and quite a bit of time at sci-fi conventions, where my father was a sci-fi book dealer. In fact […]
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10:41 AM | Paper published in PRB
Our paper “Local and nonlocal dynamics in superfluid turbulence” has now been published in PRB, and can be found at: https://journals.aps.org/prb/abstract/10.1103/PhysRevB.91.104517 Our from my publications page: http://abag.wikidot.com/publications An intersting complementary study (which I only became aware of today) was also published in PRB last year: http://journals.aps.org/prb/abstract/10.1103/PhysRevB.90.144511
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10:18 AM | Sparse sum: set cover problem in GAMS
In a set cover problem (http://en.wikipedia.org/wiki/Set_cover_problem)  we can organize the sets in two different ways: Use a (sparse) two dimensional set. The cover equation will contain a construct like: sum(c(s,i), x(s)). Use a (sparse) zero-one parameter. In this case the cover equation can have something like: sum(s, c(s,i)*x(s)). The question came up. What is better? I like the set construct a bit better but that is purely based on aesthetics. The performance is exactly the […]
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8:04 AM | Translating from Scientist to English
Stories were coming out recently about new cancer research led by Bryony Telford in Parry Guilford’s lab at Otago, and I’d thought I’d use it for an example of translation from Scientist to English. It’s a good example for news because it really is pretty impressive, because it involved a New Zealand family with familial cancer, and […]
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7:06 AM | Gimme that old time nutrition
Q: Did you see that eating a bowl of quinoa every day helps you live longer? A: No. Q: There’s story on Stuff (well, from the West Island branches). Is it true? A: Hard to say. Q: Well, does the research claim it’s true? A: Hard to say. Q: Why? Didn’t they link? A: No, they linked, […]
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5:00 AM | Improving M-SBL for Joint Sparse Recovery using a Subspace Penalty
This is very interesting. In the area of sparsity seeking solvers M-SBL is with AMP one of the interesting solvers to follow. This is in part due to the good results Zhilin Zhang got with block sparsity and non sparse signals in the past.The authors of the following paper change the regularization term of that algorithm and seem to have even better phase transitions for sparse signals. Without further ado:Improving M-SBL for Joint Sparse Recovery using a Subspace Penalty by Jong Chul Ye, Jong […]
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3:03 AM | Foreign drivers, yet again
From the Stuff front page Now, no-one (maybe even literally no-one) is denying that foreign drivers are at higher risk on average. It’s just that some of us feel exaggerating the problem is unhelpful. The quoted sentence is true only if “the tourist season” is defined, a bit unconventionally, to mean “February”, and probably not even […]
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12:52 AM | A Speed Comparison Between Flexible Linear Regression Alternatives in R
Everybody loves speed comparisons! Is R faster than Python? Is dplyr faster than data.table? Is STAN faster than JAGS? It has been said that speed comparisons are utterly meaningless, and in general I agree, especially when you are comparing apples and oranges which is what I’m going to do here. I’m going to compare a couple of alternatives to lm(), that can be used to run linear regressions in R, but that are more general than lm(). One reason for doing this was to see how much […]
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12:00 AM | A one week flipped teaching environment to introduce Object Oriented Programming
This post describes a teaching activity that is run for the Cardiff MSc. programmes. The activity is revolves around a two day hackathon that gets students to use Python and object oriented programming to solve a challenge. The activity is placed within a flipped learning environment and makes use of what I feel is a very nice form of assessment (we just get to know the students). This year is the third installment of this exercise which came as a result of the MSc advisory board requesting […]

March 24, 2015

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8:02 PM | If you're following the Mars One story, you need to read this
From Elmo Keep:A Point-By-Point Response to The Latest Claims Made By Mars One
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6:10 PM | Updated Java Utilities for CPLEX and CP Optimizer
I just finished adding a feature to a utility library I use in Java projects that employ either CPLEX or CP Optimizer. In addition, I moved the files to a new home. The library is free to use under the Eclipse Public License 1.0. The code is mentioned in previous posts, so I'll just quickly summarize the content here and refer interested parties to the earlier posts:Setting CPLEX Parameters (October 2012)Printing a CP Optimizer Model in Java (March 2014)Setting CPLEX Parameters in Java […]
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6:00 PM | Stationary Stability in Finite Populations
guest post by Marc Harper A while back, in the article Relative entropy minimization in evolutionary dynamics, we looked at extensions of the information geometry / evolutionary game theory story to more general time-scales, incentives, and geometries. Today we’ll see how to make this all work in finite populations! Let’s recall the basic idea from […]
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