Siete enigmas matemáticos que valen un millón de dólares (I)

 

Cuenta la leyenda que Alfred Nobel no contempló en su testamento la creación de un premio para los matemáticos porque el amante de su mujer era un matemático y les tenía algo de manía. Lo únco cierto de esta historia, sin embargo, es que efectivamente no existe un premio Nobel de Matemáticas. Por lo demás, lo cierto es que Nobel nunca llegó a casarse.

A falta de un Nobel, la Unión Matemática Internacional concede cada cuatro años la Medalla Internacional para Descubrimientos Sobresalientes en Matemáticas, o Medalla Fields. No es nada fácil ganar una: como decimos, se otorga cada cuatro años y solo a matemáticos menores de 40 años que hayan logrado avances fundamentales en la disciplina. Su prestigio, obviamente, es enorme.

 

http://www.elconfidencial.com/tecnologia/2014-01-30/siete-enigmas-matematicos-que-valen-un-millon-de-dolares-i_78459/

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Activar un navegador en Ubuntu de Linux

Activar un navegador en Ubuntu de Linux

Siga estas instrucciones para activar Java en el navegador Web en Ubuntu de Linux.

Google Chrome
  • Para convertirse en el usuario root, ejecute el comando su e introduzca la contraseña de superusuario. Escriba: 
    sudo -s
  • Cree un directorio denominado plugins si aún no existe. Escriba: 
    mkdir -p /opt/google/chrome/plugins
  • Vaya al directorio plugins de Google Chrome antes de crear el vínculo simbólico. Escriba: 
    cd /opt/google/chrome/plugins
  • Cree un vínculo simbólico. Escriba: 
    ln -s /usr/local/java/jre1.7.0/lib/amd64/libnpjp2.so
  • Reinicie el navegador y pruebe Java
Mozilla Firefox
  • Para convertirse en el usuario root, ejecute el comando su e introduzca la contraseña de superusuario. Escriba: 
    sudo -s
  • Cree un directorio denominado plugins si aún no existe. Escriba: 
    mkdir -p /usr/lib/mozilla/plugins
  • Vaya al directorio plugins de Google chrome antes de crear el vínculo simbólico. Escriba: 
    cd /usr/lib/mozilla/plugins
  • Cree un vínculo simbólico. Escriba: 
    ln -s /usr/local/java/jre1.7.0/lib/amd64/libnpjp2.so
  • Reinicie el navegador y pruebe Java
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Using ddrescue on a failing hard drive

Using ddrescue on a failing hard drive | Der Flounder

While I was out at MacIT last week, our Casper server sent me a notification that the “Check for failing hard drive” smart group had a member. Since that’s a club that nobody wants to be a part of, I forwarded the notification to the team at home to let them know. They were able to copy the user’s home folder data off to the server and left the box itself and its failing drive for me to take a look at when I got home. Once I took a look, the SMART status report of Failing and the weird noises from the drive made me certain that it was only a few steps short of the Choir Eternal. However, I still wanted to see if I could get the maximum amount of data off of it before its final demise. Time for ddrescue. Installing ddrescue I had a bootable utility disk and a separate drive named Backup with enough storage to hold the complete contents of the failing drive. Now I just needed to install ddrescue on the utility drive. To do this, I installed MacPorts on the utility drive and then installed ddrescue. 1. Installed MacPorts from http://www.macports.org 2. Following installation, ran the following command to get MacPorts up to date: sudo port -v selfupdate 3. Next, ran the following command to install ddrescue: sudo port install ddrescue Running ddrescue 1. Get the information on the drive you want to recover from by running the following command: diskutil list For the purposes of this example, we’ll assume that the failing drive is /dev/disk0s2 2. Use the following command to have ddrescue recover data using verbose mode to a disk image on the Backup drive: sudo ddrescue -v /dev/disk0s2 /Volumes/Backup/failing_drive_backup.dmg failing_drive_backup.log The failing_drive_backup.log part of the command will create a log file that ddrescue writes to. In the event that you need to stop ddrescue and start it again, ddrescue will read the log and use the information to pick up where it left off. Monitoring ddrescue Using the “-v” flag in ddrescue means that ddrescue will display its output in verbose mode. It should look similar like this: About to copy 9223 PBytes from /dev/disk0s2 to /Volumes/Backup/failing_drive_backup.dmg Starting positions: infile = 0 B, outfile = 0 B Copy block size: 128 sectors Sector size: 512 bytes Max retries: 0 Direct: no Sparse: no Split: yes Truncate: no Press Ctrl-C to interrupt Initial status (read from logfile) rescued: 0 B, errsize: 0 B, errors: 0 Current status rescued: 69792 MB, errsize: 0 B, current rate: 18153 kB/s ipos: 69792 MB, errors: 0, average rate: 18429 kB/s opos: 69792 MB, time from last successful read: 0 s Copying non-tried blocks… You can also use fs_usage to monitor ddrescue‘s read/write progress by using the following command: sudo fs_usage | grep ddrescue Recovery Once your data has been recovered to the disk image, hopefully you can double-click on it and have it mount. However, in the event it does not, you can try restoring from the disk image to another disk partition using the following steps. 1. Get the information on the drive you want to recover from by running the following command: diskutil list For the purposes of this example, we’ll assume that the drive we’re restoring to is /dev/disk1s3 2. Use the following command to have ddrescue recover data using verbose mode from the failing_drive_backup disk image on the Backup drive to  /dev/disk1s3: sudo ddrescue -v /Volumes/Backup/failing_drive_backup.dmg /dev/disk1s3 recovery_drive.log Once on the disk partition, you should be able to run whatever repairs are needed to get the drive to mount and access your files. Update 2-3-2012: When recovering data to a drive, you may receive the following message: ddrescue: Output file exists and is not a regular file. ddrescue: Use `–force’ if you really want to overwrite it, but be ddrescue: aware that all existing data in output file will be lost. In this case, the output file is your destination drive and ddrescue has detected that it’s an existing partition. If you’re certain you want to write to it, use -f to force overwriting of the existing partition: sudo ddrescue -v /Volumes/Backup/failing_drive_backup.dmg /dev/disk1s3 recovery_drive.log -f

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ddrescue recuperacion de datos

El comando ddrescue es una herramienta muy potenta para intentar recuperar datos de un disco duro/particion con errores.

GNU ddrescue Manual

This manual is for GNU ddrescue (version 1.13, 27 August 2010).

ddrescue

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Intel linux graphic installer

LINUX GRAPHICSIntel(R) Linux* Graphics Installer version 1.0.1

Details

Release Date: 

20 May 2013

Version: 

  • 1.0.1

Type: 

  • Installer

Intel® Linux* Graphics Installer 1.0.1

Description

The Intel® Linux* Graphics Installer allows you to easily install the latest graphics and video drivers for your Intel graphics hardware. This allows you to stay current with the latest enhancements, optimizations, and fixes to the Intel® Graphics Stack to ensure the best user experience with your Intel® graphics hardware. The Intel® Linux* Graphics Installer is available for the latest versions of Ubuntu* and Fedora*.

License

The Intel® Linux* Graphics Installer is made available under the terms of the Apache Software License 2.0. A link to the source code is provided above, which includes a copy of the License.

Packages installed by the Intel® Linux* Graphics Installer are subject to their respective copyright and license terms.

Supported Intel® Linux* Graphics Stack Releases and Linux* Distributions

Signatures – Ubuntu*

In order to “trust” the Intel® Linux Graphics Installer, you will need to add keys to Ubuntu’s software package manager (“apt”). Open a terminal, and execute these line:

wget --no-check-certificate https://download.01.org/gfx/RPM-GPG-KEY-ilg -O - | \
sudo apt-key add -
wget --no-check-certificate https://download.01.org/gfx/RPM-GPG-KEY-ilg-2 -O - | \
sudo apt-key add -

Signatures – Fedora*

In order to “trust” the Intel® Linux Graphics Installer, you will need to add keys to Fedora’s software package manager (“rpm” and “yum”). Open a terminal, and execute these lines:

wget --no-check-certificate https://download.01.org/gfx/RPM-GPG-KEY-ilg ; \
sudo rpm --import RPM-GPG-KEY-ilg
wget --no-check-certificate https://download.01.org/gfx/RPM-GPG-KEY-ilg-2 ; \
sudo rpm --import RPM-GPG-KEY-ilg-2

Installing and Running

Pick the correct Installer package for your Linux distribution, version, and architecture (32- or 64-bits). The links are provided above. Click the appropriate link to begin package installation.

Once installed, you can find the Intel Linux Graphics Installer in your application dashboard. Just look for our logo, or begin typing ‘Intel’.

If you are a power user, you can open a terminal and execute:

intel-linux-graphics-installer

Not Supported by the Installer

Reproduced from the FAQ page:

Due to the complex package dependencies of the binary graphics drivers for the Intel® Graphics Media Accelerator 3600 Series used in the Intel® Atom™ Processor N2600 Series and Intel® Atom™ Processor N2800 Series, supported drivers are only available through your device manufacturer or through Linux distributions providing support for the Intel® GMA 3600. An unsupported version of the binary driver is also available at

This software is provided ‘as-is’, without any express or implied warranty, and is bound by the license terms included with the download package.

Intel(R) Linux* Graphics Installer version 1.0.1 | Linux Graphics

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making kubuntu use less memory

i run kubuntu on a 1gb ram netbook, and optimizing KDE memory usage is cruicial for me because i use this machine for development (kdevelop is a large beast, and i want to have chromium and gcc running as well). I’d like to share a few tips to achieve that.

1. sudo apt-get install kubuntu-low-fat-settings
2. if you don’t need bluetooth: sudo apt-get purge bluez* bluedevil
3. sudo apt-get purge akonadi-backend-mysql mysql* (this will automatically install sqlite backend)
4. if you don’t use activities: sudo rm /usr/share/kde4/services/kactivitymanagerd.desktop (i filled bug 298088 with request to make kactivitymanagerd ran only when really needed)
5. if you don’t need akonadi: sudo rm /usr/share/autostart/akonaditray.desktop
6. if you don’t use nepomuk (i.e. disabled it in systemsettings): sudo rm /usr/share/autostart/nepomukserver.desktop
7. sudo rm /usr/share/autostart/kaddressbookmigrator.desktop
8. if you don’t use printer often: sudo rm /usr/share/autostart/printer-applet.desktop (you can still start this applet manually by issuing ‘printer-applet’ command in konsole)
9. sudo mv /etc/rc5.d/S50saned /etc/rc5.d/K50saned

(hint by Dave: instead of removing .desktop files, just do ‘cp FILE ~/.kde/share/autostart && echo Hidden=true >> ~/.kde/share/autostart/FILE)

Currently my Kubuntu uses 222mb right after startup.

Also i’m investigating why the programs I really need (kmix, klipper, etc) are taking so much ram. first results showed that at least 4megs are used to store font data (allocated by qHBNewFace() call in src/gui/text/qfontengine_ft.cpp, and this is not shared across different processes!)

 

Communicating the actions: making kubuntu use less memory

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Wisee, un proyecto creado sobre Ubuntu

 

Wisee, un proyecto creado sobre Ubuntu

Wisee, un proyecto creado sobre Ubuntu

Una de las principales pegas que se pone al uso de Ubuntu es “que tiene pocos usos y no me sirve”, pues bien la noticia de hoy es una gran piedra para demostrar lo contrario. Wisee un proyecto que pretende hacer que el sistema operativo reconozca nuestros gestos y movimientos, se está realizando sobreUbuntu. Hace unas horas se ha publicado un vídeo y fotos sobre este novedoso proyecto que pretende captar y reconocer los movimientos en base a las interrupciones que el cuerpo hace en el sistema de onda wifi.

 

La noticia ha sido recogida por la BBC News y a pesar del desconocimiento del sistema operativo, las imágenes no dejan duda y rápidamente ha saltado la noticia.

 

Los requisitos físicos de Wisee

Aunque el sistema de Wisee nos recuerda a Microsoft y su Kinect, Wisee por el momento usa una tecnología más cara, es decir, no se puede usar el típico router de casa o low cost de tiendas informáticas. Se desconoce las especificaciones técnicas ( protocolos usados, alcance de red, etc..) pero los expertos avanzan que el hardware usado por Wisee puede alcanzar 10 veces el precio del Kinect.

Requisitos de Software de Wisee

Respecto a los requisitos de software, ya hemos hablado de Ubuntu, desconocemos que versión, pero todo indica que será la versión 12.10 En cuanto al lenguaje de programación, se afirma usar Java. Un lenguaje bastante pesado pero que puede hacer que el software creado para Wisee pueda usarse en cualquier distribución Gnu/linux o en otros sistemas operativos.

Tal vez la noticia sobre Wisee resulte rara y atípica en el blog, pero Wiseerepresenta muy bien la idea de que Ubuntu es un sistema adaptable y adaptado a diversos públicos, para diversas tareas y por un precio muy, pero que muy económico: 0 euros.

Además es un buen ejemplo de caso en el que se supera al sólido Windows o alcool MacOS. Espero que se avance en la investigación de Wisee, sin embargo, todo parece indicar que como muchos otros proyectos, Wisee se quede en sólo software, aún así representaría un gran avance tecnológico y, realizado sobreUbuntu.

Más Información – Zorin OS, la mejor manera de dar el salto desde Windows a Linux,

Fuente – Ubunlog y  OMG!Ubuntu!

Imagen – BBC News,

Video – Wi See

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