Seen somewhere recently:
- where fractional terms are over all primes, and the sign in front of them is minus if and plus otherwise.
- paper: “Improving fluid intelligence with training on working memory” by Susanne M. Jaeggi, Martin Buschkuehl, John Jonides, and Walter J. Perrig – http://www.pnas.org/content/early/2008/04/25/0801268105.abstract
- paper: “Short- and long-term benefits of cognitive training” by Susanne M. Jaeggi1, Martin Buschkuehl, John Jonides, and Priti Shah – http://www.pnas.org/content/early/2011/06/03/1103228108.abstract
- paper: “Increasing fluid intelligence is possible after all” by Robert J. Sternberg – http://www.pnas.org/content/105/19/6791.full.pdf#page=1&view=FitH [PDF]
- “Can You Make Yourself Smarter?” By DAN HURLEY (The New York Times; 2012.04.18) – http://www.nytimes.com/2012/04/22/magazine/can-you-make-yourself-smarter.html?pagewanted=all&_r=1&
- Dual N-back game online (at Soak Your Head) – http://www.soakyourhead.com/dual-n-back.aspx [requires Silverlight 2]
- Dual N-back game online – http://www.brainboffin.com/
- Discussion at Google groups: “Dual N-Back, Brain Training & Intelligence” – https://groups.google.com/forum/?fromgroups#!forum/brain-training
- Dual N-Back FAQ – http://www.gwern.net/DNB%20FAQ
- IQ boost with dual n-back task – http://dual-n-back.com/ [with online game at http://dual-n-back.com/nback.html]
- N-back (at WikiPedia) – http://en.wikipedia.org/wiki/N-back
- Brain Workshop – a Dual N-Back game – http://brainworkshop.sourceforge.net/; free downloadable application (for Windows)
- Brain Workshop – Python implementation of the Dual N-Back mental exercise – http://sourceforge.net/projects/brainworkshop/
- Dual N-Back Lite – http://sourceforge.net/projects/dualnbacklite/
- The Brain Trainers” by DAN HURLEY (NYT; 2012.10.31) – https://www.nytimes.com/2012/11/04/education/edlife/a-new-kind-of-tutoring-aims-to-make-students-smarter.html
“Forget Brain Age: Researchers Develop Software That Makes You Smarter” by Alexis Madrigal (Wired; 2008.04.28) – http://www.wired.com/science/discoveries/news/2008/04/smart_software
- gbrainy – https://live.gnome.org/gbrainy – a brain teaser game and trainer to have fun and to keep your brain trained. | http://sourceforge.net/projects/gbrainy/
- Pathological – http://sourceforge.net/projects/pathological/ – “an engaging puzzle game in the spirit of “Logical” byRainbow Arts. To clear a level, match the rolling marbles by collectingthem into wheels. A wide variety of board elements makes the game funand challenging.”
- Jooleem – http://sourceforge.net/projects/jooleem/ – “a simple yet extremely addictive puzzle game. The best way to kill 10 minutes. There is only one rule: click on four marbles of the same color that form a rectangle. Time is constantly running out, but you can earn time by forming rectangles.”
Elsewhere in this blog: Intelligence (IQ) – https://eikonal.wordpress.com/2010/10/27/intelligence/
- Project page – http://code.google.com/p/shellinabox/
- Shell In A Box is a web server that can export arbitary command line tools to a
web based terminal emulator
- “Shell In A Box Gives Your Browser Terminal Status” by Ken Hess (2010.09.19) – http://www.linux-mag.com/id/7864/
- Shell In A Box gives you simple web-based terminal access to your Linux system.
- “How to install Shell In a Box” – http://www.acmesystems.it/shellinabox
- “shellinabox With Apache Authentication Over HTTPS 443” (scottlinux.com; 2010.12.15) – http://scottlinux.com/2010/12/15/shellinabox-with-apache-authentication-over-https-443/
- “Shellinabox” by BobJunior – http://bobjunior.com/linux/shellinabox/
- “Installing Shell In A Box – Ubuntu Server 11.04” (YouTube video) – http://www.youtube.com/watch?v=d4sgJY7-_r0
- TinyDisk – http://www.msblabs.org/tinydisk/index.php
Let’s consider the right-hand oriented orthonormal triad ( and ) assigned to a curve in 3-dimensional Euclidean space . Let this curve be parametrized by the “time” parameter associated to the “current” position of a particle moving along that curve. Instead of defining the triad as a tangential vectors (i.e. the tangential, normal and bi-normal vectors) to the at , define it based on the radius vector by .
The triad vectors satisfy following evolution equations:
where and are two angles defining the position of the particle.
In following we will look at the several choices for the force field that guides the motion of the particle via Newton’s equation .
The simplest case
For one finds:
- (radial equation of motion),
- (preservation of angular momentum),
- (i.e. the trajectory is planar).
A simple generalization
In force field one finds:
- (radial equation of motion),
- (definition of non-constant angular momentum),
- (equation guiding the evolution of the angular momentum),
- , i.e. the trajectory is (still) planar.
This system can be somehow simplified by use of instead of , and by introduction of the Binet variable :
with , , , and .
For we get:
- – the trajectory is not planar any more.
which, in Binet coordinates has following form
- WikiPedia: http://en.wikipedia.org/wiki/PCI_DSS
- Book: “PCI Compliance: Understand and Implement Effective PCI Data Security Standard Compliance, second edition – updated for PCI DSS v 1.2.1″ by Anton Chuvakin and Branden Williams – http://www.pcicompliancebook.info/
- About the PCI DSS – https://www.pcisecuritystandards.org/tech/
- PCI DSS Answers Blog and Forum – http://pcianswers.com/
- PCI Europe Forum – http://www.pcieurope.com/
- The PCI DSS User Group – http://forum.aegenis.com/
- PCI DSS News and Information – http://www.treasuryinstitute.org/blog/
- PCI DSS FAQ forum – http://pcidssfaq.org/forum/
- PCI DSS blog – http://pcianswers.com/
- Payment Card Security & IT Controls Explained – http://pcidss.wordpress.com/
- The Visa Cardholder Information Security Program (CISP) – http://usa.visa.com/merchants/risk_management/cisp.html
- article “PCI DSS auditors see lessons in TJX data breach” – http://searchsecurity.techtarget.com/news/article/0,289142,sid14_gci1245727,00.html
- PCI DSS Compliance (Parts 1&2) – http://www.windowsecurity.com/articles/PCI-DSS-Compliance.html, http://www.windowsecurity.com/articles/PCI-DSS-Compliance-Part2.html
- PCI DSS News and Information blog – http://www.treasuryinstitute.org/blog/
The Edge (edge.org) has an article by Charles Leadbeater (“CLOUD CULTURE: THE PROMISE AND THE THREAT” – http://www.edge.org/3rd_culture/leadbeater10/leadbeater10_index.html) on the dangers of the budding “cloud culture”.
The second replicators (memes) are getting organized better and better.
- Cloud security – https://eikonal.wordpress.com/2010/08/09/cloud-security/
In this posting the matrix is defined by where and are constant matrices.
The Baker–Campbell–Hausdorff theorem claims that:
where , and the lower-case letters and represent the adjoint actions of the corresponding matrices and (e.g. ).
One is frequently seeing the following series expression:
Source: T1269 = A.N.Richmond “Expansion for the exponential of a sum of matrices”; Int. Journal of Control (issue and year unknown).
- Sun and Moon rise and set data for any day (in US only) by USNO (US Naval Observatory): http://aa.usno.navy.mil/data/docs/RS_OneDay.php
Related here: Astronomy & Astrophysics – https://eikonal.wordpress.com/2011/05/09/astronomy-astrophysics/ | Astronomic tables and calculators – https://eikonal.wordpress.com/2010/01/28/astronomic-tables-and-calculators/ | Solar planetary system – https://eikonal.wordpress.com/2011/02/17/solar-planetary-system/ | Inside black holes – https://eikonal.wordpress.com/2011/04/12/inside-black-holes/ | Physics Sites – https://eikonal.wordpress.com/2010/02/12/physics-sites/
- T1266: M. Guenin: “On the Derivation and Commutation of Operator Functionals”; Helv. Phys. Act. 41, 75-76, 1968.
- ‘Most beautiful’ math structure appears in lab for first time (2010.01.07 by David Shiga) –
At YouTube: http://www.youtube.com/watch?v=NWjZD37rkhM
Lyrics ((Testa- Sciorilli) ed. Mascotte):
Signor capitano si fermi qui, sono tanto stanco, mi fermo si, attento sparano, si butti giù... sto attento, ma riparati anche tu. dimmi un pò soldato, di dove sei... sono di un paese vicino a lei... però sul fiume passa la frontiera. la riva bianca, la riva nera, e sopra il ponte vedo una bandiera, ma non è quella che c'è dentro il mio cuor. tu soldato, allora, non sei dei miei... ho un'altra divisa lo sa anche lei... non lo so perché non vedo più, mi han colpito e forse sei stato tu... signor capitano, che ci vuol far... questa qui è la guerra, non può cambiar. sulla collina canta la mitraglia... e l'erba verde diventa paglia... e lungo il fiume continua la battaglia, ma per noi due è già finita ormai. signor capitano io devo andar... vengo anch'io che te non mi puoi lasciar... non non ti lascerò, io lo so già, starò vicino a te per l'eternità. Tutto è finito, tace la frontiera, la riva bianca la riva nera, mentre una donna piange nella sera e chiama un nome che non risponderà. Signor capitano si fermi qui, sono tanto stanco, mi fermo si...
A 3D iterative mapping similar to mandelbrot mapping.
- Explanation and source code – http://www.subblue.com/blog/2008/4/16/harmonograph,/a>
- Flash applet – http://www.subblue.com/projects/harmonograph
- at WikiPedia – http://en.wikipedia.org/wiki/Harmonograph
One more infosec book for management types. I am not sure yet if it is worth reading – it got favorable SlashDot review by Ben Rothke, whose opinion I usually trust.