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# Posts

### October 25, 2014

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MONTHLY MEMORY LANE: 3 years ago: October 2011 (I mark in red 3 posts that seem most apt for general background on key issues in this blog*) (10/3) Part 2 Prionvac: The Will to Understand Power (10/4) Part 3 Prionvac: How the Reformers Should Have done Their Job (10/5) Formaldehyde Hearing: How to Tell the Truth With Statistically Insignificant Results (10/7) Blogging […]

### October 24, 2014

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It’s that time again — our Center for the Mathematics of Informaion (CMI) call for postdoc applications is now up. As I wrote last year at this same time, one of the things I really enjoy about Caltech is the fact that we always have lots of amazing postdocs floating around…  This year that is […]
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Two open source textbook authors that many in this group are familiar with sent me announcements recently (see below).  Looks like the folks at Simon Frasier are seeing if there is a viable business in offering print-on-demand versions of popular open source texts.  They've branded the effort BCCampus.From David Guichard:The BC Open Textbook Project is offering print copies of the book (Calculus, Guichard et al) in color […]
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E' un periodo che, per vari motivi, mi perdo informazioni. Per fortuna ci sono e-mail e newsletter che informano, e così accade anche per i risultati della spedizione italiana alle Olimpiadi Internazionali dell'Astronomia che dal Kirghizistan, sede della competizione, tornano con tre medaglie, un oro e due bronzi, festeggiati persino da Samantha Cristoforetti su twitter. Veniamo, però, al comunicato stampa inviatomi da Stefano Sandrelli:Sono tre, i premi vinti quest'anno dalla squadra […]

### October 23, 2014

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Re: Dick Lipton & Ken Regan • (1) • (2) Putting all thought of the Frankl Conjecture out of our minds for the moment, let’s return to the proposition in Example 1 and work through its differential analysis from scratch. Example … Continue reading →
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(This is a guest post by MohammadTaghi Hajiaghayi. His name is not a typo- the first name really is MohammadTaghi.) Due to our belief in the lack of transparency and well-defined measures in methods used by U.S News to rank CS departments in theoretical computer science (and in general), my PhD. student Saeed Seddighin and I have worked for several months to provide a ranking based on a real and measurable method of the number of papers in TCS for the top 50 US Universities. To make this […]
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I recently reviewed a manuscript for the pioneering journal PeerJ. This presented me with a quandary. PeerJ’s experiment in open reviewing is nicely outlined in their recent post, and includes two steps: reviewers can sign their reports, and authors can publish the review history alongside their accepted paper. My quandary was this: I love the second idea, and think it is an important step forward in opening up the peer review process; but I don’t like to sign my reviews.... Read more
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As we've written about before, mitochondria generate the energy required by our cells through respiration that involves using an "electrochemical gradient" as an energy store (a bit like pumping water up into a reservoir for energy storage to then harness it flowing down the gradient of a hill to turn a turbine), and produces free oxygen radicals as by-products (a bit like sparks when the engine is running hot). The fundamental importance of this machinery which not only delivers energy, but is […]
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September 2014: Error Statistics Philosophy Blog Table of Contents  Compiled by Jean A. Miller (9/30) Letter from George (Barnard) (9/27) Should a “Fictionfactory” peepshow be barred from a festival on “Truth and Reality”? Diederik Stapel says no (rejected post) (9/23) G.A. Barnard: The Bayesian “catch-all” factor: probability vs likelihood (9/21) Statistical Theater of the Absurd: “Stat on a […]

### October 22, 2014

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[The following report on BDA’14 was written by my student Mahdi Zamani] [A more polished version of this report is available HERE] Recently, Mahnush and I attended a workshop on Biological Distributed Algorithms co-located with DISC 2014. The workshop consisted of 20 talks distributed in two days and focused on the relationships between distributed computing […]
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Starting Monday, you guys should be organized in new groups. No group can have three members that are together in the current groups. When I arrive on Monday, the groups should already be formed. You guys should start working on the laboratory on Polyhedra, Chapter 7. Make sure to bring whatever materials may be needed […]
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(This post is specifically for Math 287 students.) Starting Monday, you guys should be organized in new groups. No group can have three members that are together in the current groups. When I arrive on Monday, the groups should already be formed. You guys should start working on the laboratory on Polyhedra, Chapter 7. Make […]
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The Committee for the Advancement of Theoretical Computer Science put together an open letter to several research leaders at Microsoft. We feel that there should have been a better way to close down this lab, one that would have allowed them to have continuous employment until academic jobs are available again in September 2015. Given that this lab was continuing to produce exceptional — indeed revolutionary — research, we fail to understand why closing it had to be done so suddenly. I […]
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Here is a pentagonal knitting pattern done in chemlambda, as appears after 20 steps: The knitting is made of abstraction (lambda) nodes, in the middle, bordered by fanin nodes. The knitting molecule appears after 3 steps, it can be then seen at the top of the figure. The white small molecules are loops. This pattern […]
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Come ha ricordato Maurizio Codogno è stato il centenario di Martin Gardner. Recupero oggi con la traduzione di un articolo di David Singmaster uscito su "Nature" nel 2010 come ricordo per la figura di riferimento che ha rappresentato per moltissimi lettori, amanti della matematica e matematici professionisti.Dalla metà degli anni '50 fino ai primi anni '80 del XX sexolo, probabilmente la più nota sezione di Scientific American è stata Mathematical games di Martin Gardner. Come […]
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This essay is a bit late. I wrote it about three months ago, so it rehashes tons of things from the past months of posts as if they never occurred. Still, I think the example is nice. We’ve been thinking … Continue reading →
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Almost all prediction intervals from time series models are too narrow. This is a well-known phenomenon and arises because they do not account for all sources of uncertainty. In my 2002 IJF paper, we measured the size of the problem by computing the actual coverage percentage of the prediction intervals on hold-out samples. We found […]
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The start of the academic year has a habit of bringing forth distractions, not least of all to someone as disorganized as me. So here are a few remarks in brief. The class number of is one. John Miller, a … Continue reading →

### October 21, 2014

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Come saprete i dati di BICEP che sembrava dovessero confermare l'inflazione cosmica e le onde gravitazionali primordiali hanno subito una verifica negativa. Come spiegano molto bene Amedeo e Sandro, l'interpretazione dei risultati è stata completamente ribaltata dalle analisi di Planck.Uno degli aspetti che, con quell'annuncio di metà aprile, non avevo trattato ma che mi sarebbe piaciuto era la questione dell'inflazione infinita. Questa ipotesi teorica venne introdotta da Alan Guth e altri […]
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This time we use the principle of minimum power to determine what a circuit made of resistors actually does. Its ‘behavior’ is described by a functor sending circuits to linear relations between the potentials and currents at the input and output terminals. We call this the ‘black box’ functor, since it takes a circuit: […]
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Martin Gardner was born on October 21, 1914, so today is his Centennial (he died on May 22, 2010, at the age of 95). We've mentioned him in the blog before:  The Life of Martin Gardner  Contribute to the Gardner Centennial  Another Post on Martin Gardner I used the anagram Tim Andrer Gran in both my review of the Lipton-Regan book (see here) and my Applications of Ramsey Theory to History paper (see here) So what can I add on his centennial? He was not the first person to […]
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I guess my first posted rant was the call for papers thing.  Here's a second.Countless times, from me to Chair/Dean xxx at Some Other University: I am happy to help with your evaluation of Professor zzz. This email will serve as my letter. [email here]...Countless times, from Chair/Dean xxx to me: Thanks very much for your thoughtful evaluation. Can you please put it on your university letterhead and re-send?Fantasy response from me to Chair/Dean xxx:Sure, no […]

### October 20, 2014

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Okay, today we will look at the ‘black box functor’ for circuits made of resistors. Very roughly, this takes a circuit made of resistors with some inputs and outputs: and puts a ‘black box’ around it: forgetting the internal details of the circuit and remembering only how the it behaves as viewed from outside. As […]
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At the beginning of this year I wrote an excited post announcing our new Computing and Mathematical Sciences (CMS) PhD program.  Unfortunately, the approval did not happen in time for students to apply to it last year, but everything is up and running now, so we’re looking forward to seeing the first round of applicants […]
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The Time Machine at the End of the World, di Les Edwardsvia ahiddenworld.tumblr.comCome tutti i generi, anche la fantascienza in ultima analisi è interessata a parlare dell'essere umano. In particolare, come ricorda Isaac Asimov, parla dell'essere umano contemporaneo, nascondendo il messaggio dietro una rappresentazione meravigliosa, dietro un sense of wonder dovuto a progressi scientifici inimmaginabili.I due progressi scientifici che muovono la maggior parte della fantascienza (non sono gli […]
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Let be a commutative ring. From we can construct the category of -modules, which becomes a symmetric monoidal category when equipped with the tensor product of -modules. Now, whenever we have a monoidal operation (for example, the multiplication on a ring), it’s interesting to look at the invertible things with respect to that operation (for […]
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Editor’s Note: Dr. Chandni Usha is an IQIM postdoctoral scholar working with Prof. Eisenstein. We asked her to describe her experience as an IQIM fellow. When I look back at how I ended up here, I find myself in a … Continue reading →
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José Iovino has asked me to help advertise the following: At the 2015 Joint mathematics meetings (JMM), January 10-13, in San Antonio, TX, there will be two special sessions on model theory. The first is Beyond First Order Model Theory, a special session of the ASL and the AMS. See here for the schedule, list of […]
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As this is my first post, I feel obliged to say the obligatory Hello World!. With that aside, the problem I am going to discuss comes from the popular game Sudoku. Suppose that we are given a filled Sudoku \$S\$ … Continue reading →
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If you study the philosophy of science — and sometimes even if you just study science — then at some point you might get the urge to figure out what you mean when you say ‘science’. Can you distinguish the scientific from the non-scientific or the pseudoscientific? If you can then how? Does science have […]