Mathblogging.orgRecent Postshttp://www.mathblogging.org/scripts/feed.php2015-01-27T03:17:20-05:00No copyright asserted over individual posts; see original posts for copyright and/or licensing.Mathblogging.org Atom serializerVisual Patterns Fun!http://www.mathblogging.org/post/1099312015-01-26T19:18:04-05:00mathmindsblogEach day, I start class with a math routine. Whether it is a Number Talk string, If I Know Then I Know, Closest Estimate or Quick Image, those first 10-15 minutes are always my favorite math conversations of the day! Today I added Fawn’s (@fawnnguyen) Visual Patterns into the mix. I spend a lot of […]Some fun geometry and a challenging number theory topichttp://www.mathblogging.org/post/1099292015-01-26T19:05:47-05:00mjlawlerSome days teaching the boys seem to go super well – could be some interesting ideas from them, or just general enthusiasm, but days like this make me really happy that I have the opportunity to teach them math. Yesterday my son struggled with this AMC 10 problem: Problem #14 from the 2012 AMC 10…On This Day in Math - January 27http://www.mathblogging.org/post/1099302015-01-26T19:00:00-05:00Pat Ballew*Starship Asterisk web site<br />It troubles me that we are so easily pressured by purveyors of technology into permitting so-called ‘progress’ to alter our lives without attempting to control it—as if technology were an irrepressible force of nature to which we must meekly submit.<br />~Hyman G. Rickover<br /><br />The 27th day of the year; 273 = 19,683 which has a digit sum of 27. There is no larger number for which the sum of the digits of the cube is equal to the number .<br /><br /><br />EVENTS1520 Off the Patagonian coast […]Managing Emacs windowshttp://www.mathblogging.org/post/1099282015-01-26T18:27:05-05:00JohnWhen you have Emacs split into multiple windows, how do you move your cursor between windows? How do you move the windows around? Moving the cursor between windows You can use C-x o to move the cursor to the “other” window. That works great when you only have two windows: C-x o toggles between them. […]the density that did not exist…http://www.mathblogging.org/post/1099272015-01-26T18:15:32-05:00xi'anOn Cross Validated, I had a rather extended discussion with a user about a probability density as I thought it could be decomposed in two manageable conditionals and simulated by Gibbs sampling. The first component led to a Gumbel like density wirh y being restricted to either (0,1) or (1,∞) depending on β. The density […]January 31, 2015 – Opportunity Announcementhttp://www.mathblogging.org/post/1099252015-01-26T16:59:09-05:00Metroplex Math CircleThere will not be a math circle this Saturday, however, if you are interested in attending a free problem-solving session led by Dr. Titu Andreescu, I encourage you to go to AwesomeMath Academy on January 31st between 4-5:30pm and receive excellent guidance for contests such as the AMCs, Purple Comet, and USAMTS. Information and details […]La amenaza de los inconmensurableshttp://www.mathblogging.org/post/1099242015-01-26T16:46:52-05:00cualeshttp://elteoremadecuales.com/amenaza-inconmensurables-1/
Una aportación de El teorema de cuales a la edición 5.X del Carnaval: "La amenaza de los inconmensurables (primera parte)".
Salud.
Ó.
The Hostile Brothers Problem (3)http://www.mathblogging.org/post/1099232015-01-26T16:35:00-05:00Erwin KalvelagenFollow up on http://yetanothermathprogrammingconsultant.blogspot.com/2015/01/the-hostile-brothers-problem-1.html and http://yetanothermathprogrammingconsultant.blogspot.com/2015/01/the-hostile-brothers-problem-2.html. Now some experiments that did not work. Find global solutions with Baron This is a very difficult job. One idea that may help is to add some symmetry breaking constraints: This can reduce the search space considerably. We run the equation over all i–1: in GAMS this is
[…]“The Statistical Crisis in Science”: My talk this Thurs at the Harvard psychology departmenthttp://www.mathblogging.org/post/1099222015-01-26T15:50:39-05:00AndrewIt’s noon Thursday, January 29, 2015, in William James Hall 765: The Statistical Crisis in Science Andrew Gelman, Dept of Statistics and Dept of Political Science, Columbia University Top journals in psychology routinely publish ridiculous, scientifically implausible claims, justified based on “p < 0.05.” And this in turn calls into question all sorts of more […]
The post “The Statistical Crisis in Science”: My talk this Thurs at the Harvard psychology department appeared first on Statistical Modeling, Causal Inference, and Social […]A nice problem from a Romanian Math Problem Bookhttp://www.mathblogging.org/post/1099202015-01-26T15:43:42-05:00Unknown<br />(All of the math for this problem is here)<br />My Discrete Math Honors TA Ioana showed me a Romanian Math Problem book<br />(She is Romanian) and told the following problem:<br />
<br />
<br />
(All ai in this post are assumed to be natural numbers)<br />
<br />Show that for all n ≥ 6 there exists (a1,...,an) such that 1/a12 + ... + 1/an2 = 1.<br />
<br />
(sum of reciprocals squared)<br />
<br />Normally my curiosity exceeds my ego and I would look up the answer.<br />But it was in Romanian! Normally I would ask her to read the answer to me.<br />But I was going out […]Exclusive: Former NIH lab head who faked data now working as government patent examinerhttp://www.mathblogging.org/post/1099212015-01-26T15:40:24-05:00Ivan OranskyThe former director of the X-ray crystallography lab at the National Institute of Arthritis and Musculoskeletal and Skin Diseases, part of the National Institutes of Health, who was found by the Office of Research Integrity to have faked findings in three papers, is once again earning a government salary, this time as a patent examiner, Retraction […]The post Exclusive: Former NIH lab head who faked data now working as government patent examiner appeared first on Retraction Watch.Why are we obsessed with work? How to increase productivity the clever way!http://www.mathblogging.org/post/1099182015-01-26T15:29:00-05:00JoshuaIt was not too many years ago that many workers in many occupations ended their work day at 5:00pm and did not take work home with them. Technology has greatly improved our work life, or at least that is the myth that we are fed by the big companies of Apple, Microsoft and Google. To be truthful it has affected our work life by making us always 'at work' but it has severely damaged our personal family lives. The impact on our work lives has reduced productivity! How many times have you had a
[…]Cómo construir una Curva Característica de Operación (CO) con Excelhttp://www.mathblogging.org/post/1099192015-01-26T15:18:38-05:00GEO Tutoriales
La Curva Característica de Operación (o Curva Característica Operativa) consiste en una representación gráfica que muestra para un plan de muestreo específico (n,c) la probabilidad de aceptación del lote, para varios valores de calidad del lote a la entrada p (% de unidades defectuosas). Una Curva Característica de Operación tendrá entre sus puntos uno definido por […]Deborah and Franklin Tepper Haimo Award for Distinguished Teaching of Mathematicshttp://www.mathblogging.org/post/1099152015-01-26T15:02:28-05:00Mathematical Association of AmericaMathematical Association of America posted a photo:
Winners of the 2015 eborah and Franklin Tepper Haimo Award for Distinguished Teaching of Mathematics with MAA President Robert Devaney at the 2015 Joint Mathematics Meetings. <br />
<br />
Shahriar Shahriari (Pomona College)<br />
Judith Covington (Louisiana State University, Shreveport)<br />
Brian Hopkins (St. Peter’s University)Triangulo Penrosehttp://www.mathblogging.org/post/1099172015-01-26T15:02:00-05:00Vlad AlexeevTriangulo Penrose
by Bruno Góes
http://im-possible.info/english/art/various/bruno-goes.html
Author - https://www.behance.net/brugoes
Meet Statistics summer scholar Eric Limhttp://www.mathblogging.org/post/1099132015-01-26T15:00:58-05:00Julie MiddletonEvery year, the Department of Statistics offers summer scholarships to a number of students so they can work with staff on real-world projects. Eric, right, is working on a project called Accessible graphics for data on maps with Professor Chris Wild. Eric explains: “I am working on an easy-to-use data-analysis system called iNZight that has […]More on that partition bijectionhttp://www.mathblogging.org/post/1099162015-01-26T15:00:19-05:00Unknownjessecmckeown:
Or, why not? Ask why! Fix $p$ a finite rational prime. (please don’t tell them I said that…)
A Bijection between $p$-coprime partitions of $n$ and $p$-regular partitions of $n$.
There’s a generating-functions argument for why partitions avoiding multiples of $p$ are counted by the same function as partitions which have fewer than $p$ of any part. It’s OK. Two different ways of re-writing $$ \prod_j \frac{(1 - x^{j p})}{1-x^j} $$ and parsing the expansion.
Read
[…]School fee/real-estate arithmetichttp://www.mathblogging.org/post/1099142015-01-26T14:42:28-05:00Thomas LumleyThere’s an interesting piece in the Herald arguing that the effective school fees you pay by living in one of the top school zones in Auckland aren’t great value, and that you’d be better off just paying private-school fees explicitly. It’s a good point, but I think the calculations in the article are missing something: […]Extensions of Line Bundles on the Projective Linehttp://www.mathblogging.org/post/1099122015-01-26T14:40:45-05:00DennisThe following is probably obvious to experts, as it is easy to find generalizations using google. However, this humble master’s student didn’t find this most basic case, so it’s probably worth writing down. We will be working over the projective line over a field. The basic question is that, since we know that there exist […]The Origin of Specificity in Regulated Protein Degradation Wednesday, February 18, 2015http://www.mathblogging.org/post/1099112015-01-26T14:21:37-05:00Marc W. KirschnerOne of the characteristic features of life — specificity — emerges in metabolism, information transfer from DNA to protein, embryology, immunology and virtually every other process. Its explanation on the molecular level is thermodynamic stability and structural complementarity. Yet one disturbing issue persists: the protein and nucleic acid sequences coding for that specificity are generally too small to distinguish actual partners from competitors. Similarly, protein degradation conveys […]ΜΑΘΗΜΑΤΙΚΑ ΚΑΙ ΓΛΩΣΣΙΚΗ ΔΙΔΑΣΚΑΛΙΑhttp://www.mathblogging.org/post/1099102015-01-26T13:58:00-05:00Μ+Λ<!--[if gte mso 9]>
800x600
<![endif]-->
<!--[if gte mso 9]>
Normal
0
false
false
false
EL
X-NONE
X-NONE
MicrosoftInternetExplorer4
<![endif]--><!--[if gte mso 9]>Number of the Day: 1,000http://www.mathblogging.org/post/1099082015-01-26T13:45:17-05:00Brian HershbergDuke University men's basketball coach Mike Krzyzewski scored his 1,000th career victory Sunday. That's no small feat.
Cómo determinar el Tamaño de la Muestra y el Número de Aceptación en un Muestro de Aceptaciónhttp://www.mathblogging.org/post/1099092015-01-26T13:33:58-05:00GEO Tutoriales
Un muestreo de aceptación simple esta definido por el número de unidades en la muestra n y el número de aceptación c. El tamaño de la muestra n puede variar entre una unidad hasta incluso todos los artículos del lote (que en general se representa por N). En tanto el número de aceptación c determina […]alexyar:
jessecmckeown replied to your post: jessecmckeown replied to your post “to…
That reminds...http://www.mathblogging.org/post/1099072015-01-26T12:57:21-05:00Unknownalexyar:
jessecmckeown replied to your post: jessecmckeown replied to your post “to…
That reminds me of “every two elephants converse with a unique hippopotamus; two hippoi converse with at most one elephant; given a non-conversing elephant and hippo, exactly one hippo converses with the given elephant and not with the first hippo.
what is happening
Right. So. One of the early Logicians-proper (I think it was Hilbert, but don’t trust my specific memory…) anticipated
[…]Recuerdos del II CEAM CMhttp://www.mathblogging.org/post/1099052015-01-26T12:45:28-05:00juanmtg1El pasado día 16 de enero celebramos en Albacete el II Congreso para la Enseñanza y Aprendizaje de las Matemáticas de Castilla la Mancha.<br /> Mucho esfuerzo y horas de trabajo de mis amigos y compañeros se vieron recompensados con una jornada maratoniana pero gratificante.<br /> <br /> Os dejo en primer lugar algunas fotografías que tomé durante el día
Más en ...
http://juanmtg1.blogspot.com.es/2015/01/recuerdos-del-ii-ceam-cm.html
Algebra, Geometry, Desmos, and the number line…http://www.mathblogging.org/post/1099022015-01-26T12:42:37-05:00AndrewNumber lines are wonderful tools. Simple, elegant, and useful to everything from beginning to count, to categorizing number groups, to helping students make sense of irrational numbers. So, naturally my mind started racing when my daughter handed me this. I think she intended for me to throw it away, but, sticking to the old adage […]Forms of proofshttp://www.mathblogging.org/post/1099062015-01-26T12:36:15-05:00SixWingedSeraphAbstractmath.org is a website I have been maintaining since 2005. It is intended for people beginning the study of abstract math, often a course that requires proofs and thinking about mathematical structures. The Introduction to the website and the article Attitude explain the website in more detail. One of the chapters in abstractmath.org covers Proofs. […]Q: How do I know my windmill is on straight?http://www.mathblogging.org/post/1099042015-01-26T12:28:18-05:00The PhysicistThe original question was: I got quite the challenge from my father in law. The problem is well defined, but I’m having difficulties finding a meaningful answer. The reason why he asked me is because I’m an engineering student and … Continue reading →Associate/Full Professor Position at Oxford in Algorithms or Complexityhttp://www.mathblogging.org/post/1099032015-01-26T12:12:00-05:00Paul GoldbergThe Department of Computer Science at the University of Oxford is planning to make an appointment at associate/full professor level with effect from 1 September 2015 or as soon as possible thereafter.<br /><br />Applicants should hold a PhD in computer science or a related subject and have experience in any area related to algorithms or complexity.<br /><br />The details are here. Please get in touch if you are thinking of applying, and have questions about the college system and its benefits.Super Holdhttp://www.mathblogging.org/post/1099002015-01-26T12:00:00-05:00Robert W. JerniganAs the build-up to next Sunday's NFL Super Bowl continues, more evidence is surfacing about the amazing ability of the New England Patriots to hold onto the football. First, there was the football deflation controversy, termed InflateGate by some and Ballghazi by others. Somehow 11 of the 12 balls that the Patriots used in the first half of their rainy game against the Indianapolis Colts were under-inflated by as much as 2 psi. The twelfth ball was also under-inflated but not by as much. It is […]