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Posts

July 23, 2014

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1:21 AM | Dr Nic goes to ICOTS9
I had a great time at ICOTS9. Academic conferences are a bit of a lottery, but ICOTS is two for two for me. Both ICOTS8 and ICOTS9 were winners – enjoyable, interesting and inspiring.  I’ve just returned from ICOTS9 in … Continue reading →
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1:00 AM | When I say anyone can run a charter school in Florida...
I'm afraid I may be spending too much time on the rogues' gallery of the Florida charter school scandals. It's an entertaining aspect but its importance is primarily as a symptom of flawed assumptions and a badly designed system. These sharp operators are flocking to the state because the incentives that encourage good behavior are misaligned and the checks that prevent bad behavior are missing.Functional systems don't hire people with resumes like that of Steve Gallon III.From the […]
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12:45 AM | El Nino Project (Part 6)
guest post by Steven Wenner Hi, I’m Steve Wenner. I’m an industrial statistician with over 40 years of experience in a wide range applications (quality, reliability, product development, consumer research, biostatistics); but, somehow, time series only rarely crossed my path. Currently I’m working for a large consumer products company. My undergraduate degree is in physics, […]

July 22, 2014

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9:25 PM | Haskell analog of Sweave and Pweave
Sweave and Pweave are programs that let you embed R and Python code respectively into LaTeX files. You can display the source code, the result of running the code, or both. lhs2TeX is roughly the Haskell analog of Sweave and Pweave.  This post takes the sample code I wrote for Sweave and Pweave before and […]
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8:09 PM | Size of each object in R's workspace
I’ve googled How do I find out how big my workspace is too many times … here’s the explicit code to run and hopefully the next googler sees this post: for (thing in ls()) { message(thing); print(object.size(get(thing)), units='auto') } Fin. You can stop there.   Or for a bit of context… Here’s an example code to generate objects of variable sizes where you might not be sure how big they are: require(boot) require(datasets) data(sunspot.year) system.time(boot.1 […]
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7:47 PM | Chinese Diebold-Rudebusch Yield Curve Modeling and Forecasting
A Chinese edition of Diebold-Rudebusch, Yield Curve Modeling and Forecasting: The Dynamic Nelson-Siegel Approach, just arrived. (I'm traveling -- actually at IMF talking about Diebold-Rudebusch among other things -- but Glenn informed me that he received it in San Francisco.) I'm not certain that I even knew it was in the works. Anyway, totally cool. I love the "DNS" ("Dynamic Nelson-Siegel") in the Chinese subtitle. Evidently some things just don't translate. Not sure how/where to buy it; […]
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4:51 PM | WKB approximation and the reflectionless potential
References: Griffiths, David J. (2005), Introduction to Quantum Mechanics, 2nd Edition; Pearson Education – Problem 8.12. We’ve seen that if we apply the WKB approximation to a potential well and require that the WKB wave functions match up in the region between the turning points, we get the condition where is the left turning point, […]
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4:44 PM | PageRank beyond the Web
I just completed a survey article about uses of PageRank outside of web-ranking. The paper has been submitted to a journal, and I also posted the manuscript to arXiv. David F. Gleich. PageRank beyond the Web. arXiv. cs.SI:1407.5107, 2014. The … Continue reading →
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4:27 PM | Context Aware Recommendation Systems ( Lei Tang, Xavier Amatriain)
Much like the presentation by Lei Tang (Wallmart Labs) on Adaptive User Segmentation for Recommendation at last year's GraphLab 2013 (see Slides (pdf) here and video here). Xavier Amatriain, of Netflix, made a presentation of what we should be expecting in terms of recommendation. The idea here is that most of this work cannot be static otherwise your customers just won't be responsive to it. Here are his slides and the attendant videos from the Machine Learning Summer School organized in […]
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4:06 PM | Rigor + Relevance beyond Caltech
I’ve been busy traveling for most of the last month, and so missed my chance for timely postings about a couple of exciting happenings that highlight how theory can impact practice. But, here are two that I can’t resist a quick post about, even if it is a bit late. First, this year’s ACM SIGCOMM […]
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1:41 PM | Battle of the cozy comedians: What’s Alan Bennett’s problem with Stewart Lee?
When in London awhile ago I picked up the book, “How I Escaped My Certain Fate: The Life and Deaths of a Stand-Up Comedian,” by Stewart Lee. I’d never heard of the guy but the book was sitting there, it had good blurbs, and from a quick flip-through it looked interesting. Now that I’ve read […] The post Battle of the cozy comedians: What’s Alan Bennett’s problem with Stewart Lee? appeared first on Statistical Modeling, Causal Inference, and Social […]
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1:20 PM | A subway topologist
One of my favorite books when I was growing up was the Mathematics volume in the LIFE Science Library. I didn’t own the book, but my uncle did, and I’d browse through the book whenever I visited him. I was too young at the time to understand much of what I was reading. One of […]
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1:11 PM | Crime and punishment
When I was prepping for my Slate Money podcast last week I read this column by Matt Levine at Bloomberg on the Citigroup settlement. In it he raises the important question of how the fine amount of $7 billion was determined. Here’s the key part:  Citi’s and the Justice Department’s approaches both leave something to […]
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1:00 PM | More on Florida and the looting phase of education reform
This basically picks up where the post, "We couldn't even afford one Mercedes Benz at Next Generation," left off and continues detailing the Harold Hill aspect of Florida's charter school scandals. One of the fundamental assumptions of the charter school movement is that choice and accountability make regulation superfluous.  Michigan bet heavily on that principle. Florida even more so. In the Sunshine State, there are almost no barriers to entry, The attitude has been "let everybody in […]
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6:37 AM | Links
Lasciate ogni le parentesi graffe, voi ch’entrate! “That isn’t the worst idea you’ve ever told me.” “Thanks.” “And that wasn’t necessarily a compliment.” A basket of whatfruit [1] via [2] When therapists fail to understand bisexuality Wiping out mosquitoes by making them all male Shermer rides again! Harvard digital repository draws millions of readers Sins […]
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5:00 AM | Dynamic MR image reconstruction–separation from undersampled (k,t)-space via low-rank plus sparse prior - implementation -
Benjamin Trémoulhéac just sent me the following:Dear Igor,You and your readers might be interested in my paper recently published (early view) which is about the use of the RPCA (or L+S) model in dynamic MR imaging from partial Fourier samples for both reconstruction and separation:Dynamic MR image reconstruction–separation from undersampled (k,t)-space via low-rank plus sparse priorhttp://dx.doi.org/10.1109/TMI.2014.2321190​​(This is an open access article thanks to the new policy in […]
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5:00 AM | Tensor Networks for Big Data Analytics and Large-Scale Optimization Problems
Interesting review of the TT approach:Tensor Networks for Big Data Analytics and Large-Scale Optimization Problems by Andrzej CichockiIn this paper we review basic and emerging models and associated algorithms for large-scale tensor networks, especially Tensor Train (TT) decompositions using novel mathematical and graphical representations. We discus the concept of tensorization (i.e., creating very high-order tensors from lower-order original data) and super compression of data […]
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4:30 AM | A bit of context for the Malaysia Airlines Flight 17 conspiracy theories
Over at the New Republic, Julia Ioffe has a fascinating piece on the Russian media's treatment of the downing of MH17:Did you know Malaysia Airlines Flight 17 was full of corpses when it took off from Amsterdam? Did you know that, for some darkly inexplicable reason, on July 17, MH17 moved off the standard flight path that it had taken every time before, and moved north, toward rebel-held areas outside Donetsk? Or that the dispatchers summoned the plane lower just before the crash? Or that the […]
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3:50 AM | Chad Kipfer
Chad Kipfer

July 21, 2014

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11:54 PM | Using finite automata to draw graphs
The diagram below describes a finite state machine that takes as input a description of an indifference graph, and produces as output a 1-planar drawing of it (that is, a drawing with each edge crossed at most once).Indifference graphs are the graphs that can be constructed by the following process. Initialize an active set of vertices to be the empty set, and then perform a sequence of steps of two types: either add a new vertex to the active set and make it adjacent to all previous active […]
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10:00 PM | As we were saying about 'that's where they keep the money' -- more from the League of Women Voters
Diane Ravitch's blog has an extraordinary article by Patricia W. Hall, chair of the League of Women Voters Education team in Hillsborough County, Florida. It draws heavily on the League's one-year study of charters across Florida. Good government advocates should read the whole thing but it was the deals of Ryan Construction that particularly caught my eye.Although charter schools must, by Florida law, be overseen by a non -profit board of directors, there are many ways in which for-profit […]
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9:41 PM | Video Stream: GraphLab Conference 2014
We mentioned it before, the GraphLab conference is on and it is streamed live here. The program is here (the Twitter tag seems to be #GraphLabConf )Day 1: Monday, July 21, 2014General Admission. Registration opens at 8:00am.Session 1: Data Product Pipeline in Practice9:00am Prof. Carlos Guestrin Co-Founder & CEO, GraphLab Keynote: GraphLab Strategy, Vision and Practice10:10am Baldo Faieta Social Computing Lead, Adobe Systems Algorithms for Creatives Talent Search using […]
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5:37 PM | WKB approximation and the power law potential
References: Griffiths, David J. (2005), Introduction to Quantum Mechanics, 2nd Edition; Pearson Education – Problem 8.11. We’ve seen that if we apply the WKB approximation to a potential well and require that the WKB wave functions match up in the region between the turning points, we get the condition where is the left turning point, […]
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3:40 PM | Submissions requested for the next Carnival of Mathematics
It’s been quite some time since I hosted a Carnival of Mathematics with the last one being #90 back in September 2012. I am very pleased to announce that I’ll be hosting #113 next month and am currently accepting articles.  If you’ve written a mathematical blog post recently and would like to give it more [...]
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3:13 PM | Skepticism about a published claim regarding income inequality and happiness
Frank de Libero writes: I read your Chance article (disproving that no one reads Chance!) re communicating about flawed psychological research. And I know from your other writings of your continuing good fight against misleading quantitative work. I think you and your students might be interested on my recent critique of a 2011 paper published […] The post Skepticism about a published claim regarding income inequality and happiness appeared first on Statistical Modeling, Causal Inference, […]
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2:55 PM | More Than 20 Artificially Intelligent Space Probes Were Already Not Contained in the Frame of this Picture
You've probably heard the meme about "Michael Collins being the Only Human, Living or Dead, Not Contained in the Frame of this Picture"Here is another:"By the time this picture was taken, More Than 20 Artificially Intelligent Space Probes Were Already Not Contained in the Frame of this Picture"Some folks might argue that the space probes were not intelligent since they were commanded and controlled from Earth. This is not exactly true. There was at least one algorithm running on all these […]
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1:49 PM | Everyone has a crush on me
So I have been getting some feedback lately on how I always assume everyone has a crush  on me. People know this is my typical assumption because I say things like, “oh yeah that guy totally has a crush on me.” And when I say “feedback,” what I mean is people joyfully accusing me of […]
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1:00 PM | On deck this week
Mon: Skepticism about a published claim regarding income inequality and happiness Tues: Battle of the cozy comedians: What’s Alan Bennett’s problem with Stewart Lee? Wed: A world without statistics Thurs: NFL players keep getting bigger and bigger Fri: “An Experience with a Registered Replication Project” Sat, Sun: As Chris Hedges would say: Don’t worry, baby The post On deck this week appeared first on Statistical Modeling, Causal Inference, and Social Science.
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12:59 PM | Bringing bash and PowerShell a little closer together
I recently ran across PSReadLine, a project that makes the PowerShell console act more like a bash shell. I’ve just started using it, but it seems promising. I’m switching between Linux and Windows frequently these days and it’s nice to have a little more in common between the two. I’d rather write a PowerShell script […]
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11:30 AM | The League of Women Voters weighs in on Florida's charter school scandals
Diane Ravitch has the announcement. Make sure to check out the conflict of interest list at the end:FOR IMMEDIATE RELEASEMay 27, 2014Contact:Deirdre MacnabLWVF PresidentEmail: floridaleague@earthlink.netPhone: (407) 415-4559League of Women Voters ReleasesState-Wide Study on School ChoiceTallahassee, Fla — Twenty percent of the state’s charter schools close because of financial mismanagement or poor academic standards, according to the League of Women Voters of Florida after a year-long […]
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