# Posts

### December 18, 2014

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11:58 AM | A Call For Justice #OccupyCitibank

In the beautiful words of Cleveland Browns wide receiver Andrew Hawkins: I was taught that justice is a right that every American should have. Also justice should be the goal of every American. I think that’s what makes this country. To me, justice means the innocent should be found innocent. It means that those who […]

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10:41 AM | Triangle Sum Puzzle

This is probably a consequence of being a mathematician, but I have always enjoyed number puzzles. I think that there is a general simplicity and universality in numbers that are not present in things like word puzzles, where the ability to reach a solution can be limited to the vocabulary of the user. The fact […]

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Jaynes notices how easy it is to generate “paradoxes” by finding seemingly intuitive statements which contradict the basic sum and product rules of probability theory. Jaynes illustrates this using a “paradox” popularized (but not original to) the philosopher Carl Hempel. … Continue reading →

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From the Simons Institute Workshop on Spectral Algorithms: From Theory to Practice, here is: Random Embeddings, Matrix-valued Kernels and Deep Learning by Vikas SindhwaniThe recent dramatic success of Deep Neural Networks (DNNs) in many applications highlights the statistical benefits of marrying near-nonparametric models with large datasets, using efficient optimization algorithms running in distributed computing environments. In the 1990's, Kernel methods became the toolset of
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2:23 AM | Getting into the Spirit

“Autopsy found a large fluid buildup in the pericardial sac. By the time of admission, the effusion made it grow three times its regular size that day.”

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Happiness. I passed my first edX course, one called Learning From Data, taught by Professor Yaser Abu-Mostafa. It was a cool course, covering the basics of machine learning and including a good chunk of mathematical info. More specifically, among other things, we went over,
The perceptron learning algorithm.
Differences between learning & design.
When (and how) is learning feasible.
The linear model.
This was the first time I played around with machine learning. It was very
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### December 17, 2014

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11:20 PM | Hey, I just wrote my April Fool’s post!

(scheduled to appear in a few months, of course). I think you’ll like it. Or hate it. Depending on who you are.
The post Hey, I just wrote my April Fool’s post! appeared first on Statistical Modeling, Causal Inference, and Social Science.

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Thomas Leeper points me to Diederik Stapel’s memoir, “Faking Science: A True Story of Academic Fraud,” translated by Nick Brown and available online for free download.
The post Wegman Frey Hauser Weick Fischer Dr. Anil Potti Stapel comes clean appeared first on Statistical Modeling, Causal Inference, and Social Science.

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Here is a way to do semi-surpevised learning with kernels (and even with Random Features at the very end) Learning with Fredholm Kernels by Qichao Que Mikhail Belkin and Yusu Wang. In this paper we propose a framework for supervised and semi-supervised learning based on reformulating the learning problem as a regularized Fredholm integral equation. Our approach fits naturally into the kernel framework and can be interpreted as constructing new data-dependent kernels, which we call
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If you read Talking Points Memo or the Washington Post, you've probably heard about this story from New York Magazine by up and coming journalist Jessica Pressler:Late last year, a rumor began circulating at Stuyvesant that a junior named Mohammed Islam had made a fortune in the stock market. Not a small fortune, either. Seventy-two million.An unbelievable amount of money for anyone, not least a high-school student, but as far as rumors go, this one seemed legit. Everyone at Stuy knew that
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References: Tom Lancaster and Stephen J. Blundell, Quantum Field Theory for the Gifted Amateur, (Oxford University Press, 2014) – Problem 3.1. We can write the hamiltonian for the harmonic oscillator in terms of the creation and annihilation operators as Normalization requires so the combined operator acts as a number operator, giving the number of quanta […]

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3:13 PM | Thou, thee, ye, you

Ever wonder what the rules were for when to use thou, thee, ye, or you in Shakespeare or the King James Bible? For example, the inscription on front of the Main Building at The University of Texas says Ye shall know the truth and the truth shall make you free. Why ye at the beginning […]

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3:13 PM | Thou, thee, you, and ye

Ever wonder what the rules were for when to use thou, thee, ye, or you in Shakespeare or the King James Bible? For example, the inscription on front of the Main Building at The University of Texas says Ye shall know the truth and the truth shall make you free. Why ye at the beginning […]

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2:12 PM | Statistics tutorials at PyCon 2015

I am happy to announce that I will offer two statistics tutorials at PyCon 2015 on April 9 in Montreal. In the morning session I am teaching Bayesian Statistics Made Simple, which I have taught several times before, including the last three PyCons. In the afternoon I am offering a new tutorial, Statistical Inference with Computational Methods.The whole tutorial schedule is here, along with registration information. And here are some details about the tutorials:Bayesian
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Under the heading, “Results too good to be true,” Lee Sechrest points me to this discussion by “Neuroskeptic” of a discussion by psychology researcher Greg Francis of a published (and publicized) claim by biologists Brian Dias and Kerry Ressler that “Parental olfactory experience [in mice] influences behavior and neural structure in subsequent generations.” That’s a […]
The post I’d like to see a preregistered replication on this one
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Recently I’ve seen two very different versions of what a more data-driven Congress would look like, both emerging from the recent cruddy Cromnibus bill mess. First, there’s this Bloomberg article, written by the editors, about using data to produce evidence on whether a given policy is working or not. Given what I know about how […]

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12:00 PM | Notes on HTML, XML, TeX, and Unicode

This week’s resource post: some notes on typesetting, Unicode, etc. Common Math Symbols in HTML, XML, TeX, and Unicode Accented letters in HTML, TeX, and Microsoft Word Greek letters in HTML, XML, TeX, and Unicode Unicode resources See also blog posts tagged LaTeX, HTML, and Unicode and the Twitter account TeXtip. Last week: C++ resources […]

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10:16 AM | Pi in different base

In my Analysis class today I defined the trigonometric functions and by means of the complex exponential. As usual I noted that for real we have , i.e. lies on the complex unit circle. Then I drew the following picture: This was meant to show that the real part and the imaginary part of […]

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10:10 AM | A mathematician explains the Ozone Layer

Sydney Chapman was a mathematician most remembered these days for the Chapman-Kolmogorov equations in statistics, but he was also instrumental in explaining the ozone layer. THE CHEMICAL EQUILIBRIUM IN THE DENSEST PART OF THE OZONE LAYER II. In considering the … Continue reading →

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In my recent posting on four-dimensional polytopes containing linked or knotted cycles of edges, I showed pictures of linked cycles in three examples, the (3,3)-duopyramid, hypercube, and (in the comments) truncated 5-cell. All three of these have some much more special properties: the two linked cycles are induced cycles (there are no edges between two non-consecutive vertices in the same cycle), they include all the vertices in the graph, and their intersection with any two- or […]

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Felix Herrmann followed through to yesterday's "Another Donoho-Tao Moment ?" which itself was a followup to Sunday Morning Insight: The Stuff of Discovery and Hamming's time: Scientific Discovery Enabled by Compressive Sensing and related fields. Here what he has to say:Hi Igor,I agree with your assessment that the application of CS to seismic data acquisition may not qualify as a major scientific discovery but it will almost certainly lead to major scientific breakthroughs in crustal and
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4:46 AM | Survey on k-best enumeration algorithms

When I was asked earlier this year to write a short survey on k-best enumeration algorithms for the Springer Encyclopedia of Algorithms, I wrote a first draft before checking the formatting requirements. It ended up being approximately five pages of text and seven more pages of references, and I knew I would have to cut some of that. But then I did check the format, and saw that it needed to be much shorter, approximately two pages of text and a dozen references. I don't regret doing it this […]

### December 16, 2014

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10:29 PM | RStudio Git Support

One of the assignments in the R Programming MOOC (offered by Johns Hopkins University on Coursera) requires the student to set up and utilize a (free) Git version control repository on GitHub. I use Git (on other sites) for other things, so I thought this would be no big deal. I created an account on GitHub, created a repository for my assignment, cloned it to my PC, and set about coding things. As a development IDE, I'm using the excellent (and free) RStudio, which I was happy to discover has […]

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5:15 PM | Management By Nuns

I was raised in a devout Catholic home and nuns were a big part of my youth. For example, I had to watch every nun movie ever made (e.g. Figure 1) and I attended regular religious education, which was often … Continue reading →

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3:30 PM | Another Donoho-Tao Moment ?

We always hear about the need to justify mathematics as regards to applied work. Remember this "Donoho-Tao moment"? (from this 2008 newletter)[Mark Green's] favorite moment of the program came when the NSF panel – which was simultaneously conducting its first site visit – asked: Is this interdisciplinary work? Participant David Donoho (statistics, Stanford), another major contributor to the genesis of compressed sensing, reportedly
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As I wrote about already, last Friday I attended a one day workshop in Montreal called FATML: Fairness, Accountability, and Transparency in Machine Learning. It was part of the NIPS conference for computer science, and there were tons of nerds there, and I mean tons. I wanted to give a report on the day, as […]

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2:30 PM | Infrastructure part 2

This is JosephIn the same vein as some of my recent comments on infrastructure, the latest example of tricky projects is happening on the west coast. Consider:Transit advocates are often accused, absurdly, of engaging in a “war on cars”. If we were indeed committed to such a war, I’m not sure we could have come up better with anything than this. The overruns will likely cannibalize WSDOT’s budget, including all manner of road repair and construction projects (some of which are
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2:18 PM | Expectation propagation as a way of life

Aki Vehtari, Pasi Jylänki, Christian Robert, Nicolas Chopin, John Cunningham, and I write: We revisit expectation propagation (EP) as a prototype for scalable algorithms that partition big datasets into many parts and analyze each part in parallel to perform inference of shared parameters. The algorithm should be particularly efficient for hierarchical models, for which the […]
The post Expectation propagation as a way of life appeared first on Statistical Modeling, Causal Inference, and
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I was reading an article on Stumbleupon that got me thinking about the size of the planets on a more imaginable scale – the distance between the Earth and moon. Here is a video that shows what the other planets … Continue reading →