Category Archives: Science

Notre Dame Math REU

I just began working at Notre Dame’s Summer Math REU. For the uninitiated, the Research Experiences for Undergraduates program is funded by the National Science Foundation to pay for students to work at participating universities working on research in the sciences.

There are 8 students participating in the ND Math REU this year. Together, we are working on 4 separate math problems—2 students per problem. My partner and I are investigating Totally Positive (resp. Totally Nonnegative) Matrices, namely matrices whose minors are all positive (resp. nonnegative). (Note here that by minor, I really mean the determinant of any square submatrix). (See MathWorld for a description of a Totally Positive Matrix).

At the moment, we are looking at what inequalities between minors hold true for every totally positive matrix. This theory has been worked out for principle minors for up to 5×5 matrices, and generalized to some extent over non-principle minors. While there is a lot of work in this field, at present we are examining if there is a sort of ‘extremal’ or primitive set of inequalities that generate every other valid inequality.

Hopefully I’ll be able to write a more concrete description of what we are trying to accomplish at a later date.

Also, I must mention that the campus is beautiful in the summer (well, they are doing some construction, including regilding the golden dome). I’ll try to take some action shots of the REU students and the pretty campus tomorrow.

Update: Photos

Europe!

I just got back (well, a week ago now) from a two week trip through Europe. The trip was actually a May Session Global Seminar offered through the University of Minnesota. The course was entitled “Mysteries of the Universe in the 21st Century.” Each link below goes to a gallery of pictures I took on the trip. All of the photos from the trip are on Flickr for your browsing pleasure.

To begin, we flew from Minneapolis to Detroit to Rome, and then spent 3 days in Rome sightseeing. After Rome, we stopped off in nearby Tivoli to tour Villa d’Este and Villa Adriana.

The next stop was the remote Assergi (l’Aquila) near Gran Sasso. Here we had some lectures given by researchers working in the nearby Gran Sasso Laboratory. Due to some political reasons and safety concerns, we were not allowed to tour the Gran Sasso Laboratory (which is located deep within the heart of the mountain, connected to one of the tunnels thru the mountain).

Leaving Gran Sasso, we took a bus to Florence for some more sightseeing. There was a little bit of class work when we toured the European Gravitational Observatory about an hour outside of town. The EGO is looking for gravity waves using a very large interferometer. Neat stuff, really.

After spending a few nights in Florence, we stopped for the afternoon in Pisa before continuing on to Torino. Torino was just a quick layover until we left promptly the next morning for the Laboratory in the Frejus Tunnel (you know, the one that’s closed now because of the fire that killed 2 people).

Next stop was the beautiful Geneva, Switzerland, where we stayed 4 nights to tour the nearby CERN research facilities. After the 4th night in Geneva, we drove to Montreaux located on the other side of Lake Geneva to tour an old castle, Chateau de Chillon.

We then took the TGV from Geneva to Paris, a trip which lasted about 3.5 hours. After spending 3 nights in Paris (so 2 full days of sightseeing), the trip ended and we flew home.

I’ll try to write more about my experiences when I get the chance.

iSight & iChat

When I make video connections using my iSight in iChat, I get strange errors like:

No data has been received for the last 10 seconds.

I have no idea what this means. This problem only arose after I switched to Mac OS X 10.4 (Tiger). I get this in situations where I never had a problem before. I don’t think it is a firewall issue because I can connect okay; it only seems to trigger after being connected for a little while (anywhere between a few seconds and a few minutes).

Ideas?

Court nixes FCC’s broadcast flag

Rather than try to rehash something that I don’t know enough about to describe without making some errors, I’ll point you to a few places that discuss the high impact court ruling.

Essentially, the U.S. Court of Appeals ruled that the FCC had no rights in forcing manufacturers to include copy protection technology (specifically, the “broadcast flag”) that was intended on limiting unauthorized distribution of over-the-air TV on the internet. However, introduction and mandate acceptance of such broadcast flag would have prevented much innovation in the area by essentially blocking out Open Source/Free Software from using digital television by making the drivers difficult or impossible to write for.

Cory Doctorow has a good write up of the subject at Boing Boing: V-TV DAY: WE WON THE BROADCAST FLAG FIGHT! I suggest you take a look, as this ruling is huge in terms of consumer electronics for the next few years.

As it stands now, the FCC can regain this power to institute a broadcast flag only if congress explicitly passes a law granting them that authority. But no politician wants to pass a law breaking the TV’s of their voters. With any luck, it’ll be a dead issue.

ML-1710 & Tiger

Has anybody gotten their Samsung ML-1710 printer to work with Tiger?

I’ve installed the drivers from Samsung’s website (for Mac OS X 10.3), but they do not seem to show up when I add the printer.

Flickr Pro

I bought a Flickr Pro account a few days ago and went nuts uploading files, maxing out my 2GB limit for the month of April and using 10% of May’s allowance while uploading over 1700 pictures.

If you aren’t a friend or family, some 400 of those won’t be initially visible to you. If you are a Flickr user already, leave a message here and I’ll add you as a friend. If not, either leave your email and I’ll send you a password to get in, or sign up for Flickr and leave your screenname.

I’ve also put together about 30 photo sets that should be interesting to browse.

Textile 2.0.8 & WordPress

Since the server this is running on was upgraded to PHP 5, the old Textile 2 plugin no longer functioned.

I have updated this plugin to use version 2.0.8 of the TextilePHP class. Thanks to Adam Gessaman for the original plugin.

You can download textile2.0.8-smartypants.zip or textile2.0.8-smartypants.tar.gz.

Note: This was updated from Adam’s 2.0.3 plugin (not the more recent 2.0.5 plugin) by merging the changes in the Textile.php class into the plugin using the GNU utilities diff and patch.

Tiger: First Impressions

At first, I must admit that it doesn’t seem like there is a whole lot new. Spotlight is neat, but I already had much of that functionality with Quicksilver. Dashboard is a good idea, but I’m not sure I’ll work it into my daily routine quite yet.

Here’s a list of applications and neat additions:

  • iChat
    • Ability to choose between Away and Logging Off when using Fast User Switching… this was a huge annoyance for me in the past.
    • Multiple AIM/Jabber accounts
    • Mobile users show up with the word Mobile next to their name. This means I won’t accidentally IM Gary’s phone anymore.
  • Group support is much better! (It’s actually usable now, because they adopted a method similar to how all the other IM clients do it).
  • Safari
    • RSS: I’m not sure I’ll use this here. I’m quite used to NetNewsWire.
    • Undo in forms! (Was this is Safari 1.3?)
  • New page pops up helping you get on the internet if you lack a connection when you try to load a webpage.
  • Airport/Wireless
  • The menu bar meter seems to always show more bars… nice psycological effect.
  • iCal
    • Calendar Groups (much like Folders in iPhoto, etc). Not sure what use these have.
  • Show birthdays in iCal (no need for extra programs or plugins).
  • Mail
    • Smart mailboxes
  • Different interface (unsure about my feelings on this).
  • Dictionary
    • Very useful
    • Pretty interface/font selection
  • Looks very professional
  • Preview
    • Annotation features
  • New display options (continuous pages, book mode, etc).
  • Spotlight
  • AWESOME
  • System Preferences
  • I like the ability to search for what I’m looking for. Doesn’t always pop up with what I was thinking (e.g. a search for ‘scroll’ doesn’t highlight the Keyboard and Mouse Preference Pane).
  • Grapher
  • Cool program for plotting 2D and 3D images. It won’t replace gnuplot for making graphs for papers, but it is easier to use than say Mathematica for quickly making and manipulating a 3D graph.

Update: I just remembered I posted my inpressions on the Developer Preview last July. It’s an interesting read to compare my views… some things (like Safari and iChat) were fixed up, but other problems (Dashboard) remain.