X

+

6:28 PM | Three models of chemical computing

+Lucius Meredith pointed to stochastic pi-calculus ans SPiM in a discussion about chemlambda. I take this as reference http://research.microsoft.com/en-us/projects/spim/ssb.pdf (say pages 8-13 to have a anchor for the discussion). Analysis: SPiM side – The nodes of the graphs are molecules, the arrows are channels. – As described there the procedure is to take a (huge … Continue reading Three models of chemical computing →

+

That is, if autonomous computing molecules are possible, as described in the model shown in the Molecular computers. To be exactly sure about about the factor, I need to know the answer for the following question: What is the most complex chemical computation done without external intervention, from the moment when the (solution, DNA molecule, … Continue reading Improve chemical computing complexity by a 1000 times factor, easily →

+

1:07 PM | Condolences

My thoughts are with the family and friends of my neighbor, friend and an incredibly thoughtful soul Dan who fell pursuing Mr. Everest, a victim of the quake.

+

4:36 AM | Compact objects

If is a noncommutative ring, then Morita theory tells us that cannot in general be recovered from its category of modules; that is, there can be a ring , not isomorphic to , such that . This means, for example, that “free” is not a categorical property of modules, since it depends on a choice […]

+

12:06 AM | Streaming H

Items I_i s (+ve integers, I_i \in [1,U]) arrive one after another, and for any n, after having seen n items, you have to return an approximation to H_n which is the H-index of the first n items. I_1,...,I_n (The H-index of a set of number is largest k such that there are at least k items each >= k). A student in Rutgers posed this problem.This problem has a simple worstcase solution: sing log_{1+\eps} U space, get (1+\eps) one-sided error approximation by maintaining
[…]

+

Dyadic relations enjoy yet another form of graph-theoretic representation as labeled bipartite graphs or labeled bigraphs. I’ll just call them bigraphs here, letting the labels be understood in this logical context. The figure below shows the bigraphs of the 16 … Continue reading →

+

8:39 PM | EC & Sigmetrics accepted papers are out

I’m a little late in posting about this, but at this point the schedule for Sigmetrics is up, as is the list of accepted papers at EC. So, it’s a good point to take a look at each to compare. First of all, congrats to all the folks in RSRG with paper(s)…we managed to get […]

+

8:28 PM | When is Cheryl’s Birthday?

Birthdays are a fun tradition that you get to celebrate with your friends and family once a year…that is, if you tell them when your birthday is. In a logic puzzle that has been making the rounds on the Internet, … Continue reading →

+

SCUGC 2015: The 5th Workshop on Social Computing and User-Generated Content https://sites.google.com/site/scugc2015/ June 16, 2015, Portland, Oregon. in conjunction with ACM Conference on Economics and Computation (ACM-EC 2015). SUBMISSIONS DUE: April 25, 2015 midnight EDT. The workshop will bring together researchers and practitioners from a variety of relevant fields, including economics, computer science, and social […]

+

To complete the last post, here’s Pearson’s portion of the “triad” “Statistical Concepts in Their Relation to Reality” by E.S. PEARSON (1955) SUMMARY: This paper contains a reply to some criticisms made by Sir Ronald Fisher in his recent article on “Scientific Methods and Scientific Induction”. Controversies in the field of mathematical statistics seem largely […]

+

“It is no good just finding particular instances where peer review has failed because I can point you to specific instances where peer review has been very successful,” she said. She feared that abandoning peer review would make scientific literature no more reliable than the blogosphere, consisting of an unnavigable mass of articles, most of … Continue reading A second opinion on “Slay peer review” article →

+

1:43 PM | Chenevier on the Eigencurve

Today I wanted to mention a theorem of Chenever about components of the Eigencurve. Let denote weight space (which is basically a union of discs), and let be the Coleman-Mazur eigencurve together with its natural map to It will do … Continue reading →

+

If you have not seen my previous two posts, you should read them first. Shooting a classical particle …and scattering a quantum particle In the two previous posts, I shot particles (okay, simulated the shooting on a computer) at a single potential barrier and looked at what happens. What happens when we have more than […]

+

12:26 PM | … and scattering a quantum particle

In the previous post we shot a classical particle at a potential barrier. In this post we shoot a quantum particle. Whereas the behaviour of the classical particle is governed by Newton’s laws (where the external force providing the acceleration is given as minus the gradient of the potential), we allow our quantum particle to […]

+

11:20 AM | Fifty Years of Moore's Law

Gordon Moore formulated his famous law in a paper dated fifty years and five days ago. We all have seen how Moore's law has changed real-world computing, but how does it relate to computational complexity?
In complexity we typically focus on running times but we really care about how large a problem we can solve in current technology. In one of my early posts I showed how this view can change how we judge running time improvements from faster algorithms. Improved technology also […]

+

9:19 AM | Shooting a classical particle…

Here’s a small animation of what happens when you try to shoot a classical particle when there’s a potential barrier. For small initial kinetic energies, the particle bounces back. For large initial kinetic energies, the particle goes over the hump, first decelerating and then accelerating in the process. (It may be best to watch this […]

+

7:26 PM | 311 – HW 8

HW 8 is due Tuesday, April 28, at the beginning of lecture. Work in hyperbolic geometry. Given a triangle , recall that its Saccheri quadrilateral based at is defined as follows: Let be the midpoint of and be the midpoint of . Let be the feet of the perpendiculars from and to respectively. Continuing with […]

+

7:11 PM | Categories in Control

To understand ecosystems, ultimately will be to understand networks. – B. C. Patten and M. Witkamp A while back I decided one way to apply my math skills to help save the planet was to start pushing toward green mathematics: a kind of mathematics that can interact with biology and ecology just as fruitfully as […]

+

Famously, William James held that there are two commandments that govern our epistemic life.There are two ways of looking at our duty in the matter of opinion, --- ways entirely different, and yet ways about whose difference the theory of knowledge seems hitherto to have shown very little concern. We must know the truth; and we must avoid error, --- these are our first and great commandments as would be knowers; but they are not two ways of stating an identical commandment [...] Believe truth!
[…]

+

The purpose is to understand clearly what is this story about. The most simple stuff, OK? in order to feel it in familiar situations. Proceed. Chemlambda is a collection of rules about rewritings done on pieces of files in a certain format. Without an algorithm which tells which rewrite to use, where and when, chemlambda … Continue reading A comparison of two models of computation: chemlambda and Turing machines →

+

Dyadic relations have graph-theoretic representations as directed graphs with loops, also known as pseudo-digraphs in some schools of graph theory. I’ll just call them digraphs here, letting their loopiness be taken for granted in this logical context. The figure below … Continue reading →

+

3:27 PM | Il colombre

E' il pesce che i marinai sopra tutti temono, in ogni mare del mondo. E' uno squalo tremendo e misterioso, più astuto dell'uomo. Per motivi che forse nessuno saprà mai, sceglie la sua vittima, e quando l'ha scelta la insegue per anni e anni, per una intera vita, finché è riuscito a divorarla. E lo strano è questo: che nessuno riesce a scorgerlo se non la vittima e le persone del suo stesso sangue.Io non l'avevo mai visto. Ma dalle descrizioni che ho sentito fare tante volte, l'ho subito […]

+

11:16 PM | Thinking big at Yahoo

I’m speaking in the “Yahoo Labs Big Thinkers” series on Friday 26 June. I hope I can live up to the title! My talk is on “Exploring the boundaries of predictability: what can we forecast, and when should we give up?” Essentially I will start with some of the ideas in this post, and then discuss some of […]

+

10:04 PM | Thoughts on ToME’s Adventure Mode

I’ve done several posts explaining why I think roguelikes are a great genre of game to play. It is probable that the most important feature of a roguelike for me is permadeath. For example, see this post for reasons why. … Continue reading →

+

4:07 PM | MathReviews

I will be taking a leave from BSU this coming academic year, and moving to Ann Arbor, to work as an Associate Editor at MathReviews.

+

2:42 PM | Il genio di Leander Starr

Cos'è il Genio? Una possibile definizione è: colui che riesce a scoprire un modo semplice per risolvere problemi complessi(1). In questo senso non tutti i Premi Nobel scientifici possono essere considerati dei geni, ma la definizione calza a pennello praticamente con tutti loro, esclusi quelli letterari e politici. D'altra parte questa definizione è più difficile da applicare al mondo dell'arte, dove, a mio giudizio, l'attributo di genio è decisamente abusato. E' però possibile che alcuni […]

+

You have likely heard of the new result by Ben Roco, and Li-Yang on random oracles (see here for preprint) from either Lance or Scott or some other source:
Lance's headline was PH infinite under random oracle
Scott's headline was Two papers but when he stated the result he also stated it as a random oracle result.
The paper itself has the title
An average case depth hierarchy theorem for Boolean circuits
and the abstract is:
We prove an average-case depth hierarchy theorem for Boolean […]

+

1:40 PM | Groups and Group Actions: Lecture 8.5

In which we wonder what a non-integer lecture is anyway. OK, of course there isn’t a lecture 8.5. But I promised that I’d post with questions for you to consider before lecture 9, so here is that post. Preparation for Lecture 9 Lagrange’s theorem says that the order of a subgroup divides the order of […]

+

7:23 AM | Travelling Thilaksha

One of my PhD students, Thilaksha Tharanganie, has been very successful in getting travel funding to attend conferences. She was the subject of a write-up in today’s Monash News. We encourage students to attend conferences, and provide funding for them to attend one international conference and one local conference during their PhD candidature. Thilaksha was […]

+

4:12 AM | NEYMAN: “Note on an Article by Sir Ronald Fisher” (3 uses for power, Fisher’s fiducial argument)

Note on an Article by Sir Ronald Fisher By Jerzy Neyman (1956) Summary (1) FISHER’S allegation that, contrary to some passages in the introduction and on the cover of the book by Wald, this book does not really deal with experimental design is unfounded. In actual fact, the book is permeated with problems of experimentation. […]

Sidebar

Filters

+

Stupiti che 1 non sia primo? Scopriamo insieme perché è "solo" l'unità!Abbiamo già visto come, partendo dai numeri primi, si possa sviluppare un discorso più o meno approfondito sulle fondamenta matematiche. Altrettanto fondamentale, però, si rivela provare a rispondere alla domanda su quale sia il numero primo più piccolo. E', infatti, abbastanza noto come il numero 1 sia stato ora inserito ora escluso dalla lista dei numeri primi, ottenendo in alcuni casi lo status di più piccolo tra […]

Agargun A.G. & Fletcher C.R. (1997). The Fundamental Theorem of Arithmetic Dissected, The Mathematical Gazette, 81 (490) 53-57. DOI: http://dx.doi.org/10.2307/3618768

Crandall R. & Pomerance C.B. (2005). Primes!, Prime Numbers, Prime numbers: a computational perspective 1-82. DOI: http://dx.doi.org/10.1007/0-387-28979-8_1

Caldwell C.K. & Xiong Y. (2012). What is the smallest prime?, Journal of Integer Sequences, 15 arXiv: 1209.2007v2

Citation

+

Winifred Edgerton Merrill fu la prima americana ad ottenere un dottorato in matematica presso la Columbia University nel 1886. Nella sua tesi sviluppò una rappresentazione geometrica degli infinitesimi in diversi sistemi di coordinate, utilizzando lo jacobiano per per derivare le trasformazioni tra gli integrali nei diversi sistemi.Tra matematica e astronomiaNata a Ripon, nel Wisconsin, il 24 settembre del 1862 da Emmet e Clara Edgerton, si trasferisce con la famiglia a New York intorno al […]

Kelly S.E. & Rozner S.A. (2012). Winifred Edgerton Merrill: "She Opened the Door", Notices of the American Mathematical Society, 59 (04) 504-512. DOI: http://dx.doi.org/10.1090/noti818

Citation

+

Winifred Edgerton Merrill fu la prima americana ad ottenere un dottorato in matematica presso la Columbia University nel 1886. Nella sua tesi sviluppò una rappresentazione geometrica degli infinitesimi in diversi sistemi di coordinate, utilizzando lo jacobiano per per derivare le trasformazioni tra gli integrali nei diversi sistemi.Tra matematica e astronomiaNata a Ripon, nel Wisconsin, il 24 settembre del 1862 da Emmet e Clara Edgerton, si trasferisce con la famiglia a New York intorno al […]

Kelly S.E. & Rozner S.A. (2012). Winifred Edgerton Merrill: "She Opened the Door", Notices of the American Mathematical Society, 59 (04) 504-512. DOI: http://dx.doi.org/10.1090/noti818

Citation

+

Direi che oggi pomeriggio è stato un bel respirare, al Palazzo Brera. Cristina Lazzeroni dell'Università di Birmingham è venuta alle 18 (come avevo scritto nel post precedente) per raccontare del bosone di Higgs, del modello standard e di materia e antimateria. E' una sperimentale presso l'esperimento LHCb al CERN, l'esperimento dedicato proprio alla ricerca su uno dei grandi misteri dell'universo: perché in esso c'è un eccesso di materia (e d'altra parte se non fosse così, non ci sarebbe […]

Aaij R., B. Adeva, M. Adinolfi, C. Adrover, A. Affolder, Z. Ajaltouni, J. Albrecht, F. Alessio, M. Alexander & S. Ali & (2013). First Observation of CP Violation in the Decays of B_{s}^{0} Mesons, Physical Review Letters, 110 (22) DOI: http://dx.doi.org/10.1103/physrevlett.110.221601

Citation

+

Per i I cieli di Brera, il 24 settembre (domani... scusate per il ritardo nell'annuncio...) alle 18 presso la Sala delle Adunanze dell'Istituto Lombardo nel Palazzo Brera sito in via Brera 28 (Milano), si terrà la conferenza La fisica delle particelle e il Large Hadron Collider: recenti sviluppi e questioni aperte: Cristina Lazzeroni ci introdurrà alla fisica delle particelle e agli studi fatti al Large Hadron Collider del Cern di Ginevra mettendo l’accento su recenti sviluppi come la
[…]

Aad G., J. Abdallah, S. Abdel Khalek, O. Abdinov, R. Aben, B. Abi, S. H. Abidi, M. Abolins, O. S. AbouZeid & H. Abramowicz & (2014). Measurement of the Higgs boson mass from the $H\to \gamma \gamma $ and $H\to Z{Z}^{*}\to 4\ell $ channels in $pp$ collisions at center-of-mass energies of 7 and 8 TeV with the ATLAS detector, Physical Review D, 90 (5) DOI: http://dx.doi.org/10.1103/physrevd.90.052004

Citation

rmathematicus tweeted: @rmathematicus

RT @PickeringChatto: Mary Wollstonecraft was born #otd in 1759. You can read the intro to our recent book on her philosophy free online htt…

2015-04-27 09:38:16

rmathematicus tweeted: @rmathematicus

RT @cofktweets: ...And for another great Robert Hooke resource, see the Hooke Folio Online by @livesandletters http://t.co/mnOOB92m2E

2015-04-27 09:35:37

rmathematicus tweeted: @rmathematicus

RT @cofktweets: New online resource on the library of the 17th-century virtuoso Robert Hooke (1635-1703) http://t.co/68qCNOb2vw by http://t…

2015-04-27 09:35:33

ulaulaman tweeted: @ulaulaman

Hubble vs. The Big Bang http://t.co/ig6xiZYi8G by @StartsWithABang

2015-04-27 09:30:44

rmathematicus tweeted: @rmathematicus

RT @mathshistory: Paul Gordan (1837-1912) worked on invariant theory & algebraic geometry, born 27 Apr http://t.co/ecNlyU5igT

2015-04-27 09:26:51

rmathematicus tweeted: @rmathematicus

RT @historical_iris: Zodiac man from a 1399 almanac, used by physicians to explain astrological medicine to patients. #medhist #science htt…

2015-04-27 09:26:42

rmathematicus tweeted: @rmathematicus

Can somebody do me a PDF of this please http://t.co/1Ee86epRRU I don't subscribe

2015-04-27 09:26:26

ulaulaman tweeted: @ulaulaman

What is the Strong Force? http://t.co/tEzbdFSMHk

2015-04-27 09:20:20

X