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viernes, mayo 30, 2008

Spirit: Gramáticas flexibles en C++

Una extensión de la librería Boost para generar gramáticas compilables en C++.
Podría usarse para crear nuestro propagador de restricciones.

A simple EBNF grammar snippet:

group ::= '(' expression ')'
factor ::= integer | group
term ::= factor (('*' factor) | ('/' factor))*
expression ::= term (('+' term) | ('-' term))*

is approximated using Spirit's facilities as seen in this code snippet:

group = '(' >> expression >> ')';
factor = integer | group;
term = factor >> *(('*' >> factor) | ('/' >> factor));
expression = term >> *(('+' >> term) | ('-' >> term));

Through the magic of expression templates, this is perfectly valid and executable C++ code. The production rule expression is in fact an object that has a member function parse that does the work given a source code written in the grammar that we have just declared. Yes, it's a calculator. We shall simplify for now by skipping the type declarations and the definition of the rule integer invoked by factor. The production rule expression in our grammar specification, traditionally called the start symbol, can recognize inputs such as:

Elogio de C++

Con enlaces a las librerías más super - potentes de C++

What Makes a Programming Language Successful?
Let me emphasize one thing here: I don't think C++ is the pinnacle of programming. Far from it. But its undeniably powerful, and there is no other language that has this amount of expressiveness and range. Java and C# are severely limited in comparison. Python and Lisp are much more flexible, but at the cost of performance. Where else can I write metaprograms that construct a code path at compile-time, for example? With all the compile-time optimizations applied to the result?

I also gave examples already. Try replicating Boost.Fusion or Boost.Proto in C# or Java. Try replicating Blitz++, or Spirit. Try generic programming in C++, then in Java and C# (you'll curse at the latter two's generics). Look up what's possible with C++ metaprograms (-> Boost.MPL & Fusion). Read books from Scott Meyers and Alexei Alexandrescu (especially Modern C++ Design).


Librería BSD para almacenar en base de datos una estructura de grafo, de forma eficiente. Free software.
e4Graph logo
e4Graph Introduction
The e4Graph library enables your program to represent and manipulate graph-like data efficiently and to store this data persistently. The overhead for persistence is etremely low, so e4Graph is useful also for when you do not care about keeping the data around between runs of your program; you can use it purely as a data structure library, without concern for persistence.

The key benefit provided by e4Graph is that it frees you to think about your data structures and the relations between the various entities without worrying about how to build the data structure and how to efficiently store it. Your program accesses and manipulates the data according to the relationships it represents, and e4Graph takes care of how to represent the data efficiently and persistently. Data is loaded into the executing program on demand, as a connection from an already loaded item to an on-disk item is followed; this data loading step is transparent to your program, and in-memory storage is recovered automatically when the data is no longer accessible by your program. This allows e4Graph to efficiently manipulate data graphs whose sizes are several orders of magnitude larger than the machine's available memory.

Interpretación de programas de ordenador

Libro online HTML, incluye conceptos de creación de arquitectura de software basados en minilenguajes. Abstracción layers, definición de un programa en capas...

Structure and Interpretation of Computer Programs
The picture language exercises some of the critical ideas we've introduced about abstraction with procedures and data. The fundamental data abstractions, painters, are implemented using procedural representations, which enables the language to handle different basic drawing capabilities in a uniform way. The means of combination satisfy the closure property, which permits us to easily build up complex designs. Finally, all the tools for abstracting procedures are available to us for abstracting means of combination for painters.

We have also obtained a glimpse of another crucial idea about languages and program design. This is the approach of stratified design, the notion that a complex system should be structured as a sequence of levels that are described using a sequence of languages. Each level is constructed by combining parts that are regarded as primitive at that level, and the parts constructed at each level are used as primitives at the next level. The language used at each level of a stratified design has primitives, means of combination, and means of abstraction appropriate to that level of detail.

jueves, mayo 29, 2008

El mejor bar de tapas de España

Buscamos la mejor caña de España - rtve.es
Buscamos la mejor caña de España

Ver mapa más grande

Colabora con nosotros en el 'mapa de las cañas'. Buscamos la mejor caña de España con vuestra ayuda. Añade en el mapa dónde consideras que se sirve la mejor caña del país, indicando el precio, por qué crees que es la mejor, como es la tapa que la acompaña (si la hay), dirección del bar, etc.

Macros en Firefox

Firefox extensions, para grabar tareas automatizadas

Instantly Build a Useful Macro Library for Firefox | OStatic
Recording macros with iMacros consists of simply turning a record function on and performing your tasks. There is no coding on your part, so if you, like many people, think of macros as tools for programmers and eggheads, definitely think again.

miércoles, mayo 28, 2008

YOXOS: Configurador de Eclipse automático

Servicio de descarga de plugins del IDE Eclipse, que gestiona las dependencias.

Yoxos On Demand Eclipse Download Service
Yoxos On Demand: Free Eclipse Download Service
EclipseEclipse On Demand
Download. Update. Share. Now entirely free!

* Get Eclipse 3.3 Europa plus hundreds of plugins.
* Choose plugins and add them to your download.
* Get all dependencies resolved automatically.
* Single file download.
* Free update service.
* For Windows, Linux and Mac OS X.Yoxos On Demand Eclipse Download Service

Estructuras de datos altamente concurrentes, en Java

Programación paralelizable / paralela multicore multi trhead multiprocesador.
Slashdot | Scalable Nonblocking Data Structures Programming
"InfoQ has an interesting writeup of Dr. Cliff Click's work on developing highly concurrent data structures for use on the Azul hardware (which is in production with 768 cores), supporting 700+ hardware threads in Java. The basic idea is to use a new coding style that involves a large array to hold the data (allowing scalable parallel access), atomic update on those array words, and a finite-state machine built from the atomic update and logically replicated per array word. The end result is a coding style that has allowed Click to build 2.5 lock-free data structures that also scale remarkably well."
Scalable Nonblocking Data Structures
These operations may need no OS system call, may use no explicit semaphore or lock, but the memory bus has to be locked briefly -- especially to guarantee all CPUs seeing the same updated value, it has to do a write-through and cannot just update the values in cache local to the CPU. And when you have large number of CPU cores running, the memory bus becomes the bottleneck by itself.

That's not strictly true.

First, most lock operations do not require a full bus lock. All you have to do is to ensure atomicity of the load and store. Which effectively means you have to 1) acquire the cache line in the modified state (you're the only one who has it here), and 2) prevent system probes from invalidating the line before you can write to it by NACKing those probes until the LOCK is done. Practically this means the locked op has to be the oldest on that cpu before it can start, which ultimately delays its retirement, but not by as much as a full bus lock. Also it has minimal effect on the memory system. The LOCK does not fundamentally add any additional traffic.

Second, the way the value is propagated to other CPUs is the same as any other store. When the cache line is in the modified state, only one CPU can have a copy. All other CPUs that want it will send probes, and the CPU with the M copy will send its data to all the CPUs requesting it, either invalidating or changing to Shared its own copy depending on the types of requests, coherence protocol, etc. If nobody else wants it, and it is eventually evicted from the CPU cache, it will be written to memory. This is the same, LOCK or no.

Third, an explicit mutex requires at least two separate memory requests, possibly three: One to acquire the lock, and the other to modify the protected data. This is going to result in two cache misses for the other CPUs, one for the mutex and one for the data, which are both going to be in the modified state and thus only present in the cache of the cpu that held the mutex. In some consistency models, a final memory barrier is required to let go of the mutex to ensure all writes done inside the lock are seen (x86 not being one of them).

Fourth, with fine enough granularity, most mutexes are uncontested. This means the overhead of locking the mutex is really just that, overhead. Getting maximal granularity/concurrency with mutexes would mean having a separate mutex variable for every element of your data array. This is wasteful of memory and bandwidth. Building your assumptions of atomicity into the structure itself means you use the minimal amount of memory (and thus mem bw), and have the maximal amount of concurrency.

So basically, while it isn't necessarily "radical" (practical improvements often aren't), it is definitely more than bogus marketing. There's a lot more to it than that.

martes, mayo 27, 2008

Minigolf cuántico

Juego de minigolf con licencia GPL. Las reglas son las mismas, pero la bola está hecha de fotones y se mueve como una onda y una partícula a la vez.

Quantum Minigolf
A quantum ball (right, colored) propagating towards the hole (left, yellow). The obstacle shown is the infamous "double slit". Move the mouse over the image to see a nice shot.

jueves, mayo 22, 2008

La historia secreta de La Guerra de las Galaxias

La evolución completa de los guiones del universo StarWars, con montones de fuentes nunca antes publicadas. Por y para fans de SW.

The Secret History of Star Wars

What is it?

The Secret History of Star Wars is a new full-length e-book exploring the writing and creation of the Star Wars saga. Culled from over 400 sources and filled with quotes from people such as George Lucas, Gary Kurtz and Mark Hamill, The Secret History of Star Wars traces all the way back to 1973 to examine how the first 14-page treatment that began the series came to be and was slowly built, draft by draft, year by year and movie by movie. Covering a period of over four decades, you will discover how George Lucas got his ideas for the original film, how Darth Vader was made into Luke Skywalker's father in 1978 and forever altered the arc of the story, what happened to the infamous third trilogy in the series and how the prequel stories came to be. The book also reveals the style and method of Lucas himself and how his personal life affected and shaped the story, for better and worse. This is a book which challenges many legends surrounding the series and places the films in a new light. For the more casual fan this will be a mesmerising read and for those who think they know everything about the series, prepare to be surprised!

40 juegos de iconos para web, gratuitos

40 Professional Icon Sets For Free Download | Graphics | Smashing Magazine
In the overview below we present 40 excellent, free and professional icons for desktop and web design. Some of them can be used for both private and commercial projects. You may always use them for fre in your private projects.Freebies Icons - Office Space Icon Set

Dolores que no hay que ignorar

Dolores de alerta : Siete molestias que no debes ignorar - Enfermedades - Consejos en como prevenirlas
a veces, los dolores indican que algo malo está pasando con tu cuerpo. Aquí te decimos cuáles son esas molestias por las que no debes dejar de consultar a un especialista.

Tempus Fugit: 7 Dolores que jamás deberías ignorar
Otra nueva entrada que puede ser tan útil como el artículo de los 10 Mitos Peligrosos o Inútiles sobre Primeros Auxilios siempre que se tomen con sentido común.

Tempus Fugit: 10 Mitos Peligrosos o Inútiles sobre Primeros Auxilios
Si prueba alguno de estos mitos, puedes correr el riesgo de tener una reacción adversa o un resultado opuesto a lo que quería que sucediera. Así que aquí tenemos 10 correcciones clásicas de emergencia que, definitivamente, no lo serán en apuros.

Foto del día: 6,697 fotos, hasta su muerte

miércoles, mayo 21, 2008

CSPLib: archivo de problemas CSP de restricciones

Modelado de problemas de restricciones CSPs, biblioteca - colección - archivo.


: a problem library for constraints

Logos corporativos cambiados: herejías capitalistas

Mario Amaya, diseñador de São Paulo hizo una serie de
modificaciones en logotipos conocidos mezclándolos con los de
otras marcas. De esta forma el logo de Adobe se convierte en el de
Apple o el de Ferrari en el de Ford...

Sr. Notícia: Surreal

martes, mayo 20, 2008

Apple core logos

Apple Mac OS X Leopard core api logo sound animation gui


And so, in Leopard, Apple has introduced Core Animation. It gets a snazzy purple sphere icon to go with its friends.

Core Image logo
Core Image

Core Audio logo
Core Audio

Core Video logo
Core Video

Altereconomía: economistas independientes en Internet

Blog de opinión económica alternativa

Altereconomia - Qué es Altereconomía
AlterEconomía es un proyecto de un grupo de economistas que tratamos de pensar y divulgar los hechos económicos desde otro punto de vista, más crítico e interesado principalmente por las facetas de la actividad económica que más afectan al bienestar humano, que suelen ser las que tienen que ver con el dinero y las finanzas, con la distribución de la renta, con la comunicación... y, en general, con el poder y la política.

AlterEconomía quiere aprovechar la influencia inmensa de internet para distribuir contenidos que normalmente no se difunden a través de los grandes medios de comunicación, precisamente, porque son los que mejor ayudan a entender la realidad económica, a descubrir cómo actúan los grandes poderes económicos y a desvelar lo que se pretende que quede oculto a la inmensa mayoría de los ciudadanos.

Además, AlterEconomía pretende hacerlo de la manera más sencilla e intuitiva posible, tratando de divulgar más que de profundizar, porque no tiene pretensión académica, sino que es un portal más bien interesado en la concienciación y en la movilización social que fortalezca los proyectos progresistas transformadores.

miércoles, mayo 14, 2008

OCU: comparativa de bombillas de bajo consumo

Bombillas de bajo consumo (OCU Compra Maestra nº 323) - Newsletter OCU Informa Contenido Global
Compras Maestras

Tienen sus limitaciones: no son recomendables para el exterior (no soportan bien el frio), tardan unos minutos en emitir toda su luminosidad (mejor no colocarlas en el cuarto de baño) y su larga vida se acorta si se encienden y apagan frecuentemente. Por lo demás, son las bombillas del futuro: gastan menos que las normales y duran mucho más. Además, gracias a la gran variedad de formatos que hay, colocarlas en las lámparas que tenemos en casa no es un problema.

- Bombillas estándar. Si tenemos en cuenta los resultados de nuestras pruebas el título de Mejor del Análisis es para para Sylvania Mini Lynx Spiral (de 9,95 a 16,30 euros) y Ikea Sparsam (3,50 euros), esta última, además, por su buena relación calidad/precio también recibe el galardón de Compra Maestra. Si quiere ahorarse unos euros, nuestra Compra Ventajosa recae en Auchan Primer Precio Ahorradora de energía (de 2,45 a 3,95 euros) de Alcampo.

- Bombillas tipo globo. En esta categoría la Mejor del Análisis es Philips Economizadora Globo 8 years (de 17,50 a 29,89 euros). Por su buena relación calidad/precio la Compra Maestra es para Lexman Extralife (de 5,95 a 6,95 euros).

Microsoft CAB: lecturas recomendadas

Documentación para aprender a manejar la tecnología de capa de presentación de GUI de Microsoft para crear interfaces de usuario RAD.

Never In Doubt: "Why CAB?" Webinar Feedback
Can you recommend something to read about CAB/SCSF?

A: We took a stab at this in the webinar. It's not as easy to read about CAB as it should be. For the most part, you have to poke around in many places and cobble together your own training course.

The place to start is the Microsoft Patterns and Practices site: http://www.codeplex.com/smartclient.

Cajones fractales

Documentación HOW TO

Cómo añadir usabilidad a la documentación de tu programa

Usability in Technical Documentation
Technical writers are involved at a very late stage in the product-development life cycle due to which the quality of the documentation suffers.

1. Time bound deliverables

Due to late involvement; technical writers are bounded to create documents with a quick turn around time.

2. Closely associated with the development team hence they are

a. Dictated by the product development team

b. Biased and tend to use technical jargons

c. More focused on the functions and features rather than the user’s tasks

3. No access to the actual users

Technical writers usually don’t have an in-dept knowledge about the target audience for whom they are catering to hence the documentation-

a. Does not speak the user’s language

b. Reflects a lot of cultural issues

Technical writers can overcome these challenges by

* Getting the organization to have “Technical Writing” as a planned activity
* Involving them in the early stage of the product life cycle
* By creating “User Focused Usable” documents, which is the most critical activity Testing documents of a product with “actual” users is key to create “Usable” documents.

Cubo de Rubik para torpes

Solución sencilla para resolver el cubo de Rubik

Beginner Solution to the Rubik's Cube Solved Rubik's Cube

Futbol chapa

Juego de fútbol con chapas, para windows y linux, hecho en españa

Como jugar « Pro Evolution Chapping - Blog
El juego consiste en meter más goles que el contrario. Cada equipo tendrá tres movimientos para intentar meter un gol. Puedes usarlo para mover la misma chapa tres veces, o una vez tres chapas distintas, etc. Si en algunos de estos movimientos se toca la pelota el turno se pierde automáticamente, a no ser que el balón quede tan cerca de un compañero que podrá hacer un movimiento extra, vamos lo que se llamaría un pase.

Y tu pareja, ¿a qué tipo informático pertenece?

Analogía “Pareja - Informática” | Humor, Informática, Varios, en Gran Angular Blog
Y tu pareja, ¿a qué tipo informático pertenece? (vale la comparación seas hombre o mujer)

* Pareja Virus: Cuando menos lo esperas, se instala en tu apartamento y va apoderándose de todos tus espacios. Si intentas desinstalarlas, vas a perder muchas cosas; si no lo intentas, pierdes todas.
* Pareja Internet: Hay que pagar para tener acceso a ella.
* Pareja Servidor: Siempre está ocupada cuando la necesitas.
* Pareja Windows: Sabes que tiene muchos fallos, pero no puedes vivir sin ella.
* Pareja Macintosh: Preciosa, infalible y algo cara, no muy compatible con otras… y solo el 5% de la gente saben la dicha de tenerlas.
* Pareja PowerPoint: Ideal para presentarlas a la gente en fiestas, convenciones, etcétera.
* Pareja Excel: Dicen que hace muchas cosas, pero tú tan solo la utilizas para la operación básica.
* Pareja Word: Tiene siempre una sorpresa reservada para ti y no existe nadie en el mundo que le comprenda totalmente.
* Pareja D.O.S.: Todos la tuvieron algún día, pero nadie la quiere ahora.
* Pareja Backup: Tu crees que tiene lo suficiente, pero a la hora de ‘vamos a ver’, le falta algo.
* Pareja Scandisk: Sabemos que es buena y que sólo quiere ayudar, pero en el fondo nadie sabe lo que realmente está haciendo.
* Pareja Screensaver: No sirve para nada, pero te divierte.
* Pareja Paintbrush: Puro adobito y nada de sustancia.
* Pareja RAM: Aquella que olvida todo apenas se desconecta.
* Pareja Disco Duro: Se acuerda de todo, todo el tiempo.
* Pareja Mouse: Funciona sólo cuando la arrastras y la presionas.
* Pareja Multimedia: Hace que todo parezca bonito.
* Pareja Usuario: No hace nada bien y siempre esta haciendo preguntas.
* Pareja e-Mail: De cada diez cosas que dice nueve son tonterías.
* Pareja Refrigeración Líquida: Por mucho que te esfuerces nunca se calienta.

lunes, mayo 12, 2008

Fotos de la WWII... en color


Según dicen los expertos, la película Kodachrome 4x5 fue
una de las mejores de la historia, y gracias a que estas
imágenes fueron tomadas sobre este tipo de película, han
podido ser restauradas a una calidad tal que parecen haber sido tomadas
ayer mismo. Sin embargo, se trata de fotografías realizadas
durante la Segunda Guerra Mundial. La nitidez y brillo de los colores
es impresionante.

TuttoRolleiForum - 60 anni fa: Kodachrome 4x5

El libro de dos pingüinos gay, el más censurado en EEUU

bobolongos: ¡Salvemos a los pingüinos gays!
Algunas de las otras peligrosas y lascivas obras que este año han alcanzado el top-ten son: La brújula de oro, de Philip Pullman –se dice que promueve el ateísmo…-, Olive’s Ocean, de Kevin Henkes, o la recurrente saga Harry Potter –ya en 2001, un iluminado de EEUU decidió armar una fogata con libros del mago de Rowling-, acusada de apostar por la brujería y fomentar el uso de la mentira en los niños.

El libro de dos pingüinos gay, el más censurado en EEUU
La Asociación Americana de Bibliotecas ha publicado esta semana su lista anual de los “10 Most Challenged Books of 2007”, algo así como los 10 libros más cuestionados de 2007. Por segundo año consecutivo, el cuento para niños And Tango Makes Three, de Justin Richardson y Peter Parnell, editado en España por RBA (Tres con Tango, 2006), ha sido el libro que ha sufrido más intentos para ser retirado de los planes de estudio o bibliotecas públicas. Una historia de dos pingüinos gay que adoptan un huevo huérfano basada en un caso real

Tutorial 1080p: por qué merece la pena

Secrets of Home Theater and High Fidelity - High Definition 1080p TV: Why You Should Be Concerned
The downside on an interlaced format is that the alternating fields only truly compliment each other if the subject is stationary. If it is, then the alternating fields "sum" to form a complete and continuous 1920 x 1080 picture (everything lines up perfectly between the two fields). If the subject moves though, it will be in one position for one field and another position for the next. The interlaced fields no longer compliment one another and artifacts such as jaggies, line twitter, and other visual aberrations are a normal side effect of the interlaced format. Deinterlaced Wrong1080i: se pierde resolución en toda la escena
Deinterlaced Correct1080p: sólo pierde resolución el objeto en movimiento

El famoso bug del croma en los DVD

Incluye una descripción de los formatos de compresión de video MPEG.

DVD Player Benchmark - Chroma Upsampling Error
Chroma Formats

For decades, video engineers have known that the eye is much less sensitive to color information than grayscale information. This is physiological in nature: the retina of the eye has more gray-sensitive cells, called "rods," than color-sensitive cells, called "cones." Your eyes can resolve much finer details in black and white than in color. For this reason, it's not necessary to store full color resolution on a video recording system. Your eye can't resolve it, so why waste space (money) for it?

sábado, mayo 10, 2008

Librería para Javascript que aprovecha herencia por prototipos

Slashdot | Processing Visualization Language Ported To Javascript
Can someone please explain to me why anyone would regard jquery as a black mark on John Resig's work?

I've found it very useful for anything but the most mundane js tasks. Certainly better than the piles of other libraries that all seem to be based around the fallacy that javascript needs classical inheritance. (Hint: It doesn't. It has prototypal inheritance.)

viernes, mayo 09, 2008

Herramienta web para crear fuentes de letra

Tipos de letra online
Slashdot | Make Your Own Fonts, In a Web Browser

"Although it's been up for a few weeks, today is the official launch of FontStruct, a web-based font creation tool. That's right: in your web browser, you can build your own typeface, and download it as a TrueType font. The site's user agreement requires you to release your creations online under one of the Creative Commons licenses. The typefaces tend to be a little blocky, but it's still impressive (and a great way to pass time)."

Fold It! Juego científico de doblado de proteínas

Como Fold@Home, pero con procesador basado en células grises!

Solve Puzzles for Science | Fold It!
Thanks to all you wonderful protein folders, we had a successful launch today with tons of great press. We even survived the Slashdot Effect! The team posts automatic updates very often, so keep playing and expect to see some awesome new features over the next couple weeks. Thank you for playing Foldit. Now let's solve some puzzles for science!

miércoles, mayo 07, 2008

El esquema de fracaso del liberalismo puro

Pequeño ejemplo económico que presenta una situación injusta, a pesar de ser conforme a las normas morales del liberalismo.

Journal of spun (1352)
Consider the simplified case of three property owners, A, B, and C. Here's what their property looks like:
Now, A and C make an agreement not to buy any of Bs goods or sell anything to B. B doesn't own enough land to support him and all his family living there. He doesn't have enough land for an airport, or a helicopter. A and C won't let him on their property, and they won't let anyone else deliver anything to him over their property either. B and his family starve to death, then A and C split his land between themselves.

Please, explain how this scenario or more complex variants of it would not be commonplace in a true libertarian system. "Force" is more complex than libertarian philosophy likes to admit.

Design Eye for the Web Guy

Rediseños de páginas web famosas, hechos por profesionales de la usabilidad. Por ejemplo, incluyen el diseño de la web de Jakob Nielsen (Alertbox)

DesignEye.org http://designeye.org/de_dirk.jpg
* Design Eye for South By SXSW 2008
* Design Eye for the List Guy SXSW 2006
* Design Eye for the Idea Guy SXSW 2005
* Design Eye for the Usability Guy 2004 (as seen in Communication Arts)

What the heckfire is this?

Design Eye is an experiment in bringing fresh vision to existing web design. And like all experiments, Design Eye features a few random theories and a group of mad scientists who put them to the test. The Design Eye team uses its individual expertise and collective talent to tackle each project as a soup-to-nuts strategic redesign. From content to usability to aesthetics, a freshly scrubbed and newly enlightened project emerges from every fashion-forward, fun-packed makeover.

martes, mayo 06, 2008

Memorresistencia: nuevo tipo de componente electrónico

NeoFronteras » Nuevo componente electrónico fundamental - Portada - Noticias de Ciencia y Tecnología - Noticias
Las memorresistencias construida ahora por los Laboratorios HP, de escala nanométrica, podría tener un gran impacto en la industria microelectrónica ya que podría servir para construir memorias no volátiles para computación, cuyos datos no desaparezcan aunque se corte el aporte de corriente. Además consumirían menos energía.
El 1971 Leon Chua de University of California en Berkeley notó una ausencia en la lista de los componentes habituales de los circuitos. Cada elemento expresa una relación entre dos de cuatro variables electromagnéticas: carga, corriente, voltaje y flujo magnético. Propuso que, teóricamente, debería de haber un componente que se hiciera más o menos conductor al paso de la corriente dependiendo de la cantidad de carga que hubiera pasado a través de él. Según Chua la memorresistencia o memorresistor sería el cuarto componente fundamental de los circuitos, con propiedades que no podrían ser duplicadas mediante la combinación de los otros tres elementos.

Economía de los créditos

Fresh Family Office. Gurús de la Felicidad y la Riqueza: El Vendedor de Tiempo vs. el Vendedor de Créditos.
este video titulado Money As Debt (Traducido al español aquí pero con baja calidad), que me ha recomendado mi Amigo y colega Global Counsellor. De todos los videos y documentos que relatan el orígen del dinero y sus perversos efectos causados por el abuso en la construcción de castillos de naipes financieros, éste me parece diáfano en su primera mitad.

Barra de extensión GPL para el Explorer

Incluye comandos habituales: crear carpetas, renombrar varios ficheros (bulk), abrir shell en directorio actual...

StExBar | Stefan's Tools
the StExBar provides many useful commands for your everyday use of Windows explorer. And you can add as many custom commands on your own as you like.
StExBar screenshotStExBar screenshot

Buenos buscadores de viajes

Los mejores buscadores de viajes, vuelos y hoteles. Comparadores con fecha y hora, y que permiten escoger la hora de vuelo.

Kayak.es Kayak.es
Una vez que hayas elegido, te enlazamos con los sitios de viajes que correspondan para que efectúes tu compra. Kayak te permite elegir un sitio donde realizar tu compra: una agencia de viajes en línea o un consolidador como Orbitz o Airfare.com. El motor de búsqueda de Kayak puede encontrar todo tipo de productos de viaje, desde vuelos y hoteles hasta coches de alquiler y cruceros.

SkyscannerSkyScanner Ltd
¿Por qué es distinto Skyscanner?

* Queremos mostrarte tantos precios como sea posible
* Queremos permitirte buscar esos precios con la mayor facilidad y flexibilidad posible
* Si no tenemos el precio de una compañía aérea concreta, te lo diremos para que puedas buscar otras opciones
* Cuando accedes a sitios de compañías aéreas o agencias de viajes desde nuestros vínculos, nuestro propósito es transferir toda la información que has introducido para ahorrarte tiempo

Supersaver es el nuevo centro de viajes para viajeros inteligentes.
Viajeros que quieren comprar el mismo viaje pagando menos.
Viajeros que pueden elegir entre más de 1.500 salidas diarias y más de 30.000 hoteles en más de 8.500 destinos.
Viajeros que reservan y pagan directamente con tarjeta.
Viajeros que prefieren hacer sus propias reservas.
Viajeros que prescinden de servicios que encarezcan su viaje.
En resumen… viajeros inteligentes!

Trabber busca vuelos baratos en 45 sitios simultáneamente

lunes, mayo 05, 2008

HOW TO: Concentrarse en el trabajo

Cómo mantenerse concentrado en el trabajo, evitar interrupciones y hacer que cada minuto cuente.

16 Ways to Keep A Razor- Sharp Focus at Work | Zen Habits
Focus is something that must be fought for. It’s not something that automatically switches on when you want to. You have to make sure your surroundings are perfect for working if you want to be focused. Here’s a few ways I’ve found this to work:
  1. Use offline tools. Paper products, pens, and other
    physical tools are a Godsend for those of us who have a hard time
    focusing throughout the work day. They’re so simple that we can
    use them quickly, without having to worry about becoming distracted.
  2. Take more breaks. More breaks = More productivity.
    It may sound wrong, but it’s true. Breaks allow us to re-group
    our thoughts and focus for the task at hand. They also keep us fresh so
    that we don’t end up burning out after only a few hours work.
  3. Smaller tasks to check off. When you’re
    planning your day, make sure that your “action steps” (aka
    items in the checklist) are small actions. Instead of “Paint
    living room”, try breaking it down into many tasks, like
    “buy paint, buy rollers, pick colors” etc.
  4. Keep a steady pace. Don’t try to do to much.
    Keeping the pace manageable allows you to keep your focus.
    Unfortunately, people can confuse this with “Work till you drop
    without breaks”. See number 2.
  5. Keep a daily “purpose” card.
    It’s pretty easy to get lost staring at the computer all day
    long. We’ll find rabbit holes to wonder down (ie. Youtube,
    Myspace, etc.) if we’re not careful. Having your daily purpose
    card gives you clarity and a reminder as to what you’re doing
  6. Develop the mindset that the computer is only a tool.
    It’s easy to try and use the computer for too much. At its core,
    the computer is merely a tool (albeit a freakin’ awesome one)
    that allows to do work more efficiently. If we’re using it as
    something more than that, (like as a solution for your life),
    you’ll ultimately fail. It’s like trying to eat a steak
    dinner with only a spoon.
  7. Plan your day to the T. If you’re finding
    sporadic periods of laziness throughout the day, it could be because
    you don’t take enough breaks (see #2), and you don’t have
    the day mapped out as efficiently as you could. Make sure your list of
    todos has lots of small, actionable steps that can be done quickly.
    This will gives a really satisfying feeling when you’re crossing
    things off your list like crazy.
  8. Notice your lazy routines. Everyone has recurring
    lazy spots throughout the day. Plan to have your breaks for those
    times. You’re going to be lazy then anyway, right?
  9. Plan the night before. Planning the night before
    is a great way to really get focused on the next day.
    “Sleeping” on your tasks and goals for the following day
    can really help your mind expect what’s going to happen the next
    day. Essentially, you’re preparing your mind for the following
    day. Advanced focus.
  10. Turn off extra inputs. These are IM and email for
    me, but we all have our Achilles heel. Completely turn off any
    distracting piece of technology that you own. Every one of these inputs
    tries to steal bits of your focus. And they won’t rest until they
  11. Set time limits for tasks. There’s no motivation like a deadline. Giving yourself real deadlines
    is a great way to stay motivated and focused on the task. Given the
    fact that we human are natural procrastinators, it’s no surprise
    that we’ll take as long as we’re allowed to finish
    something. Setting real but attainable limits is a great way to keep
    the project humming, so to speak.
  12. Keep a journal of what you did throughout the day.
    I like to use a moleskine notebook for my lists just so I can go back
    and review it every now and again, to see what I’ve done. Knowing
    how far you’ve come can keep you sharp and motivated to finish.
  13. Use programs to track where you spend your time.
    This is a real eye-opener. Knowing just how much time you spend every
    day/week/month on a certain site or with a certain program can quickly
    show you where your priorities lie. I recommend Rescue Time, but there are many others.
  14. Visualize the day in the morning, before it starts.
    A little pre-work meditation on the day’s events is a great way
    to start the day off focused and productive. Don’t worry about a
    full 30 minute session, a quick review before you start the day is fine.
  15. Start the day right. Starting the day with a good
    breakfast, some quiet time and/or exercise is a great way to set your
    day up for success. Sounds like a cliche, but it really works.
  16. Clean yourself up. It’s why my track coach
    in high school made us dress up for big races: you perform the way you
    feel. And if you feel polished, groomed and ready, you’ll be more
    likely to be productive. For me this is just taking a shower, brushing
    my teeth and putting on casual clothing. I used to work all day without
    taking a shower in my PJ’s, but I never got much stuff done.
    Let’s be honest here… if you’re dressed really
    casually, odds are you’ll be working really casually. Just taking
    the time to clean up a bit before you buckle down for the day is never
    a bad idea.

Tutorial Haskell: programar un compilador de Scheme

Cómo aprender el lenguaje Haskell a tope con un caso práctico: programar un embedded domain-specific language

Write Yourself a Scheme in 48 hours
Most Haskell tutorials on the web seem to take a language-reference-manual approach to teaching. They show you the syntax of the language, a few language constructs, and then have you construct a few simple functions at the interactive prompt. The "hard stuff" of how to write a functioning, useful program is left to the end, or sometimes omitted entirely.

This tutorial takes a different tack. You'll start off with command-line arguments and parsing, and progress to writing a fully-functional Scheme interpreter that implements a good-sized subset of R5RS Scheme. Along the way, you'll learn Haskell's I/O, mutable state, dynamic typing, error handling, and parsing features. By the time you finish, you should be fairly fluent in both Haskell and Scheme.

Faceted browsing - UI implementations

Artículo sobre implementaciones y conceptos de navegación facetada.

Digital Web Magazine - User Interface Implementations of Faceted Browsing
There are two primary methods for applying faceted filters:

* En masse—traditional form submission where multiple criteria are submitted at once
* On selection—Ajax-like technique where filtering criteria are submitted individually, sequentially upon each selection