Free Online Classes

Stanford http://openclassroom.stanford.edu/MainFolder/HomePage.php
http://scpd.stanford.edu/ppc/iframes/dataMiningCourses.html
Carnegie Mellon: http://oli.web.cmu.edu/openlearning/forstudents/freecourses
Michigan: http://open.umich.edu/
Berkeley: http://video.google.com/ucberkeley.html
MIT: http://ocw.mit.edu/courses/ http://mitworld.mit.edu/
Notre Dame: http://ocw.nd.edu/
Open University (UK): http://www.open.ac.uk/openlearn/
Fulbright (economics): http://ocw.fetp.edu.vn/home.cfm
Yale: http://oyc.yale.edu/
Khan Academy: http://khanacademy.org

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Ask HN: What programming blogs do you read daily?

this stuff never seems to be highly upvoted on HN anymore, and if it gets to +30 there's only a few comments, i speculate because new-school HNers don't understand or care. so i track them myself. best two advanced swegr blogs ever: reply http://prog21.dadgum.com/ -- swegr, fp theory http://www.johndcook.com/blog/ -- swegr, fp theory other advanced swegr blogs. we're not talking atwood and joel, here, that stuff is for college kids. http://blog.tmorris.net/ -- swegr, fp/tactics http://james-iry.blogspot.com/ -- fp/tactics http://playingwithpointers.com/ -- philosophy, fp/tactics life http://www.jasonshen.com/ -- "Art of Ass Kicking" (life) http://www.sebastianmarshall.com/ -- "Strategy, Philosophy, Self-Discipline, Science. Victory." (life) http://dilbert.com/blog -- politics & life fwiw, after having digested much of this material, I've moved on to reading all the interesting whitepapers I can find, mostly via my social networks. That's the really advanced stuff. I've been meaning to collect them and summarize many to post to HN. nag me.

Financial world dominated by a few deep pockets

http://www.sciencenews.org/view/generic/id/333389/title/Financial_world_dominated_by_a_few_deep_pockets
September 24th, 2011; Vol.180 #7 (p. 13)

A central core of extremely powerful actors (red dots) dominates international corporate finance, a new mathematical analysis finds.

  Conventional wisdom says a few sticky, fat fingers control a disproportionate slice of the world economy’s pie. A new analysis suggests that the conventional wisdom is right on the money.
Diagramming the relationships between more than 43,000 corporations reveals a tightly connected core of top economic actors. In 2007, a mere 147 companies controlled nearly 40 percent of the monetary value of all transnational corporations, researchers report in a paper published online July 28 at arXiv.org.
“This is empirical evidence of what’s been understood anecdotally for years,” says information theorist Brandy Aven of the Tepper School of Business at Carnegie Mellon in Pittsburgh.
The analysis is a first effort to document the international web of relationships among companies and to examine who owns shares — and how many — in whom. Tapping into the financial information database Orbis, scientists from ETH Zurich in Switzerland examined transnational companies, which they defined as having at least 10 percent of their holdings in more than one country. Then the team looked at upstream and downstream connections, yielding a network of 600,508 economic actors connected through more than a million ownership ties.
This network takes on a bowtie shape, with a large number of diffuse actors in the wings and a few major players tangled up in the tie’s knot. So while it’s true that ownership of publicly held corporations is broadly distributed, says complex systems scientist James Glattfelder, a coauthor of the new work, “take a step back and it’s all flowing into the same few hands.”
While any man on the street may have predicted this outcome, the economic literature portrays markets as so dynamic that they lack hot spots of control, Glattfelder says.
Researchers aren’t sure what to make of the core’s interconnectedness. On the one hand, it could expose the whole network to risk.
“Imagine a disease spreading,” says Aven. “If you have a high school where everyone’s sleeping together and one person gets syphilis, then everyone gets syphilis.”
But on the flip side, she notes, interconnectedness can lead to better self-policing and positive behaviors, such as fair labor practices or environmentally friendly policies.
And even though the status of many players in the analysis has changed drastically since 2007 (now-defunct Lehman Brothers is a key element of the core), the analysis shows that ownership is becoming increasingly concentrated and increasingly transnational, says Gerald Davis of the University of Michigan in Ann Arbor.
Because interpreting and analyzing these kinds of data is difficult, he says, the analysis serves more as “an impression of the moon’s surface you get with a telescope. It’s not a street map.”
Ownership can be difficult to study internationally because holding shares in a mutual fund doesn’t necessarily mean the same thing in the U.S. as it does in communist China. And even within a single country ownership can be hard to tease out, says economist Matthew Jackson of Stanford University. For example, when an individual invests in a mutual fund or even purchases shares through an institution like Merrill Lynch, the firm is often still the official owner of the assets. And even when shareholders do have voting rights, they may not exercise them.
“This becomes worrisome if everyone is like me and says I’ll let Vanguard do the voting,” says Jackson. “Maybe we should be a little bit worried. I don’t know if we should be.”

File Attributes on ext3 file system

Files and directories in Linux file systems have read, write and execute permissions
associated with user, group, and others. However, there are also other attributes that
can be attached to files and directories that are specific to certain file system types.
For example, most of the present day distributions use the ext3 file system. In ext3 we can set other attributes to files and directories. Let us have a quick look. Run the following command in a terminal.

$ lsattr

------------------- ./Videos
------------------- ./apt.html
------------------- ./screenshot.bmp
------------------- ./Music
------------------- ./Documents
------------------- ./Pictures
------------------- ./examples.desktop
------------------- ./Templates

See the output . The dashes against each file directory represent the various attributes that can be set.

The ext3 has 13 such attributes. They are

a (append only)
c (compressed)
d (no dump),
i (immutable),
j (data journalling),
s (secure deletion), t (no tail-merging),
u (undeletable),
A (no atime updates),
D (synchronous directory updates),
S (synchronous updates), and
T (top of directory hierarchy).


These attributes can be manipulated with chattr command.

Here are some examples:
$ sudo chattr +i screenshot.bmp
$ sudo chattr +A -R examples.desktop


$ lsattr screenshot.bmp

----i-------- screenshot.bmp


As shown in the preceding example, with the +i option set, the screenshot.bmp file
becomes immutable, meaning that it can’t be deleted, renamed, or changed, or have a
link created to it. Here, this prevents any arbitrary changes to the file. (Not even the
root user can change the file until the i attribute is gone.) You can use this to help
protect system files.


To remove an attribute with chatter, use the minus sign (-). For example:

$ sudo chattr -i screenshot.bmp

The man pages of chattr has additional info on various attributes.