ConnectBot es, en mi humilde opinión, el mejor cliente SSH para Android. Nos permite conectarnos de forma segura a nuestro servidor SSH, ya sea directamente o mediante la creación de un túnel SSH que sirva de proxy al resto de aplicaciones. La manera más segura de conectarnos es mediante la utilización de claves. Este es un sistema de autenticación basado en criptografía asimétrica, más seguro que utilizar simples contraseñas. ConnectBot no sólo permite utilizar claves, sino que también nos permite crearlas e importarlas. Para poder conectarnos a nuestro servidor sin necesidad de utilizar contraseñas, lo primero será que éste esté configurado para aceptar claves. En particular, en el fichero /etc/ssh/sshd_config, debemos tener la directiva: ...

In the beginning there was NCSA Mosaic, and Mosaic called itself NCSA_Mosaic/2.0 (Windows 3.1), and Mosaic displayed pictures along with text, and there was much rejoicing. And behold, then came a new web browser known as ”Mozilla”, being short for ”Mosaic Killer,” but Mosaic was not amused, so the public name was changed to Netscape, and Netscape called itself Mozilla/1.0 (Win3.1), and there was more rejoicing. And Netscape supported frames, and frames became popular among the people, but Mosaic did not support frames, and so came ”user agent sniffing” and to ”Mozilla” webmasters sent frames, but to other browsers they sent not frames. ...

The code behind the Google doodle celebrating Alan Turing’s 100th birthday is now up on Google code. This animated logic puzzle game appeared on the Google homepage on June 23, 2012. If you missed it, you can still play it in the doodle archives. Our doodle for Turing’s 100th birthday showed a live action Turing Machine with twelve interactive programming puzzles. Turing Machines are theoretical objects in formal logic, not physical things, so we walked a fine line between technical accuracy and accessibility. We focused on finding a good representation for programs and choosing puzzles of appropriate complexity. We did considerable user testing and iteration, more than for any past doodle. ...

Millones de impulsos llegan al cerebro desde distintos sentidos. Millones llegan incluso desde un sentido como la vista. El cerebro tiene múltiples áreas de procesamiento. En la vista por ejemplo se procesa en centros distintos el color, la forma o el movimiento. Cada impulso recorre un camino diferente al resto. Algunos son más largos y otros son más cortos. Por lo tanto, tardan distinto tiempo en llegar al cerebro. ¿Cómo sabe el cerebro que dos impulsos que sucedieron a la vez pero llegan en distinto momento son en realidad simultáneos? ...

This Knowledge Base was put together and is maintained by Roberto Salgado, Co-Founder of Websec. It is a compilation of books, papers, cheatsheets and testing done by Roberto over the years. » Roberto Salgado | websec.ca

This page gives brief, visual reference for the most common commands in git. Once you know a bit about how git works, this site may solidify your understanding. » Mark Lodato | marklodato.github.com

Debates over technology, technique, and process often go nowhere because the participants are arguing from different levels of aspiration. You’re unlikely to convince someone they should switch to programming Ruby for its beauty, if they’re merely looking to make a living as a single consultant serving local businesses in Schaumburg, Illinois. Questions such as ”does this run on my existing web host?” or ”will my clients want something their nephew web designer hasn’t even heard of?” matter far more. Their aspirations are local, finding something that (sorta) works, and getting paid. ...

Aparentemente esta pregunta parece absurda, ¿Como no van a existir los bellos colores de los paisajes que podemos observar a diario? El azul del cielo, el verde de las hojas de los árboles… parece evidente que los colores existen y son uno de los atributos más fundamentales de todos los objetos que observamos. Sin embargo, como veremos a continuación la respuesta a esta pregunta es asombrosa e inesperada. Lo primero que tenemos que hacer para tratar de responderla es analizar brevemente como y por que vemos los objetos que nos rodean. ...

Even in times of a growing market of specialized NoSQL databases, the relevance of traditional RDBMS doesn’t decline. Especially when it comes to the calculation of aggregates based on complex data sets that can not be processed as a batch like Map&Reduce. MySQL is already bringing in a handful of aggregate functions that can be useful for a statistical analysis. The best known of this type are certainly: COUNT(x), SUM(x), AVG(x), MIN(x), MAX(x), STD(x) In addition, there are a number of statistical evaluations which are also worthwhile - if not even more interesting and meaningful, but with MySQL only producible with greater efforts. What about the different averages? The harmonic average, a weighted average or the geomean? What is in the course of this with the aggregate product? How do we determine the mode, the median? The covariance? ...

We provide pre-built images for several open-source operating systems. Please note that: Every image contains the latest software as of the day the image was built. Performing updates is on your own, and may require looking for documentation to read using your favourite search engine. Default usernames and passwords, where required, can be found next to the download link of each image. You are warmly invited to create your own user, or at least to change passwords, if you intend to use the images in a public environment. ...