hidden motives

The four big software vendors — Microsoft, Oracle, IBM, and SAP — have hidden motives that customers need to understand, otherwise they might be pushed into buying products and services that don’t fit their needs.

That’s the takeaway from a recent Gartner talk in Australia, reported by IT News.
At a symposium this week, Gartner analyst Dennis Gaughan explained what the four big vendors are really trying to do, based on Gartner’s experience with its clients.

  • Microsoft mainly wants to protect Windows and Office. Microsoft is a platform company, and its main goal is to protect its highly lucrative Windows and Office monopolies, while establishing other platforms that will be hard for customers to break away from later. New functionality is “drip fed” to users of those core platforms, but new products exist to protect the core. He advised extreme caution before moving to Office 365, and said not to slip into an “all-Microsoft” mentality.
  • Oracle products don’t really work well together. Oracle’s sales force is extremely aggressive about pushing a suite of products, but has much fewer integration points than SAP. In fact, integration is usually left entirely up to the customer. Oracle is also very reluctant to talk about product roadmaps for fear that future products will cannibalize existing ones. The company makes more than 90% of its profits through maintenance fees, and will do whatever it takes to keep those fees flowing in. Gaughan also expressed some surprise that so many customers keep working with Oracle despite reporting that Oracle is “the most difficult vendor to deal with.”
  • IBM wants to take over your IT strategy. IBM bills itself as a thought leader, but its real business is selling consulting services. To thrive, IBM account managers try to take control of a company’s IT strategy so they can keep pushing new products. Gaughan recommends taking a collaborative or partner approach.
  • SAP confuses customers with pricing. A lot of SAP customers ask Gartner for help figuring out SAP’s pricing and licensing, as SAP has unusual terms for billing data going into and out of systems. Gaughan also said that a big technology transition that was driving SAP revenue for the last few years — moving existing customers from the old R/3 system to the newer Business Suite — is almost done, which means SAP will have to be more aggressive with maintenance fees. He recommended locking in maintenance prices now.

Overall, Gaughan said that most of the innovation being done in these companies is in their research arms. Their real goal is protecting the status quo for as long as possible.

Read more: http://www.businessinsider.com/what-microsoft-oracle-ibm-and-sap-dont-tell-customers-2011-11#ixzz1exOLGF8I

La Biblioteca de Babel

La biblioteca de Babel es un cuento del escritor argentino Jorge Luis Borges, aparecido por primera vez en la colección de relatos El jardín de senderos que se bifurcan (1941), colección que más tarde fue incluida en Ficciones (1944). La biblioteca parece ser infinita a la vista de un ser humano común, pero al tener un limite de 410 páginas por libro, 40 renglones por página y 80 símbolos por renglón el número de posibilidades es vasto pero finito.

http://es.wikipedia.org/wiki/La_biblioteca_de_Babel

http://www.temakel.com/artborgesbabel.htm

http://www.jornada.unam.mx/2008/08/31/sem-gustavo.html

Continue reading “La Biblioteca de Babel”

Blogger does not have a File Manager

BLOGGER: LINKING TO A PDF OR WORD DOCUMENT IN A POST

To do this in Blogger is a little different than with Typepad because Blogger does not have a File Manager.  Instead, you can use a free service from Google called Google Docs (http://docs.google.com).

http://www.blogsbyheather.com/2009/01/blogger-linking-to-a-pdf-or-word-document-in-a-post.html

un paso más cerca de lograr que las personas paralíticas caminen y usen brazos artificiales

Sao Paulo, Brasil.- Tras un experimento en que monos movieron y sintieron objetos usando únicamente su mente, los científicos suponen que están un paso más cerca de lograr que las personas paralíticas caminen y usen brazos artificiales.

Los animales fueron capaces de operar un brazo virtual para buscar objetos a través de su actividad cerebral que fue captada por implantes, una denominada interfaz cerebro-máquina.

Los primates también fueron capaces de experimentar la sensación del tacto, un elemento crucial de cualquier solución para paralíticos debido a que les permite juzgar la fuerza utilizada para agarrar y controlar objetos.

“Este fue uno de los pasos más difíciles y el hecho de que lo hayamos logrado abre la puerta al sueño de que una persona pueda caminar de nuevo”, dijo Miguel Nicolelis, neurólogo brasileño que formó parte del estudio realizado por un equipo de la Universidad de Duke, en Carolina del Norte.

Los resultados sugieren que sería posible crear una especie de “exoesqueleto” robótico que la gente podría usar para sentir objetos, afirmó.

“El éxito que hemos tenido con primates nos hace creer que los humanos podrían realizar las mismas tareas mucho más fácilmente en el futuro”, declaró Nicolelis.

El estudio fue publicado hoy en la revista especializada Nature.

En la primera parte del experimento, los monos rhesus fueron premiados con comida por usar sus manos para controlar un mando en busca de objetos en la pantalla de un computador.

Entonces el mando fue desconectado, lo que dejó a los monos con el control de un brazo virtual en la pantalla sólo a través del poder cerebral.

Nicolelis dijo que su objetivo es usar la tecnología para permitir a un atleta parapléjico joven participar en la ceremonia de apertura del Mundial de fútbol del 2014 en Brasil.

A partir del 2012, el estudio será llevado a Brasil, anticipó Nicolelis, y será puesto en práctica en el Instituto de Neurociencias en el estado norestino de Natal.

QR codes

A QR code (abbreviated from Quick Response code) is a type of matrix barcode (or two-dimensional code) first designed for the automotive industry. More recently, the system has become popular outside of industry due to its fast readability and comparatively large storage capacity. The code consists of black modules arranged in a square pattern on a white background. The information encoded can be made up of any kind of data (e.g., binary, alphanumeric, or Kanji symbols)[1]

Malicious QR codes combined with a permissive reader can put a computer’s contents and user’s privacy at risk. QR codes intentionally obscure and compress their contents and intent to humans.[19]They are easily created and may be affixed over legitimate QR codes.[20] On a smartphone, the reader’s many permissions may allow use of the camera, full internet access, read/write contact data,GPS, read browser history, read/write local storage, and global system changes.[21][22][23]
Risks include linking to dangerous websites with browser exploits, enabling the microphone/camera/GPS and then streaming those feeds to a remote server, exfiltrating senstive data (passwords, files, contacts, transactions),[24] and sending email/SMS/IM messages or DDOS packets as part of a botnet, corrupting privacy settings, stealing identity,[25] and even containing malicious logic themselves such as JavaScript[26] or a virus.[27][28] These actions may occur in the background while the user only sees the reader opening a harmless webpage. [29]

Animaciones

1: Motor radial de un avión

2: Distribución oval

3: Principio de la máquina de coser

4: Movimiento de Cruz de Malta – de la mano del segundero, que controla al reloj

5: Mecanismo de cambio de velocidades (automóvil)

6: Junta universal para velocidad constante automática

7: Sistema de carga de proyectiles

8: Motor giratorio – motor de combustión interna, el calor y no el movimiento del pistón, causa el movimiento giratorio

9: Motor en línea – cilindros alineados en forma paralela

flops in Matlab

Somebody asked how one may count the number of floating point operations in a MATLAB program.
Prior to version 6, one used to be able to do this with the command flops, but this command is no longer available with the newer versions of MATLAB.
flops is a relic from the LINPACK days of MATLAB (LINPACK has since been replaced by LAPACK). With the use of LAPACK in MATLAB, it will be more approrpiate to use tic andtoc to count elapsed CPU time instead (cf. tic,toc).
If you're interested to know why flops is obsolete, you may wish to read the exchanges in NA digest regarding flops.
Nevertheless, if you feel that you really do need a command to count floating point operations in MATLAB, what you can do is to install Tom Minka's Lightspeed MATLAB toolbox and use the flops counting operations therein.


@cise.ufl.edu>

@cise.ufl.edu>
To count flops, we need to first know what they are.  What is a flop?

LAPACK is not the only place where the question "what is a flop?" is
relevant. Sparse matrix codes are another.  Multifrontal and supernodal
factorization algorithms store L and U (and intermediate submatrices, for
the multifrontal method) as a set of dense submatrices.  It's more
efficient that way, since the dense BLAS can be used within the dense
submatrices.  It is often better explicitly store some of the numerical
zeros, so that one ends up with fewer frontal matrices or supernodes.

So what happens when I compute zero times zero plus zero?  Is that a flop
(or two flops)?  I computed it, so one could argue that it counts.  But it
was useless, so one could argue that it shouldn't count.  Computing it
allowed me to use more BLAS-3, so I get a faster algorithm that happens to
do some useless flops.  How do I compare the "mflop rate" of two
algorithms that make different decisions on what flops to perform and
which of those to include in the "flop count"?

A somewhat better measure would be to compare the two algorithms based an
external count.  For example, the "true" flop counts for sparse LU
factorization can be computed in Matlab from the pattern of L and U as:

        [L,U,P] = lu (A) ;
        Lnz = full (sum (spones (L))) - 1 ;    % off diagonal nz in cols of L
        Unz = full (sum (spones (U')))' - 1 ;  % off diagonal nz in rows of U
        flops = 2*Lnz*Unz + sum (Lnz) ;

The same can be done on the LU factors found by any other factorization
code. This does count a few spurious flops, namely the computation a_ij +
l_ik*u_kj is always counted as two flops, even if a_ij is initially zero.

However, even with this "better" measure, the algorithm that does more
flops can be much faster.  You're better off picking the algorithm with
the smallest memory space requirements (which is not always the smallest
nnz (L+U)) and/or fastest run time.

So my vote is to either leave out the the flop count, or at most return a
reasonable agreed-upon estimate (like the "true flop count" for LU, above)
that is somewhat independent of algorithmic details.  Matrix multiply, for
example, should report 2*n^3, as Cleve states in his Winter 2000
newsletter, even though "better" methods with fewer flops (Strassen's
method) are available.

Tim Davis
University of Florida
davis@cise.ufl.edu@cise.ufl.edu>

x = A b; in Matlab

x = A b;

  1. Is A square?
    no => use QR to solve least squares problem.
  2. Is A triangular or permuted triangular?
    yes => sparse triangular solve
  3. Is A symmetric with positive diagonal elements?
    yes => attempt Cholesky after symmetric minimum degree.
  4. Otherwise
    => use LU on A (:, colamd(A))