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A New Home!

I recently decided to try Amazon’s EC2 service. They have a free tier for one year that allows for more usage per month than I’ll likely ever exceed. So I decided to try it out. I got myself a shiny new Fedora 64-bit Micro instance and am now using that to host my homepage, blog, and git server. I’ve also migrated this blog there. So the new URL is: jrupac.roopakalu.com/blog.

I’ll be posting there from now on!

 
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Posted by on December 17, 2011 in Uncategorized

 

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Google!

It’s been many months since I’ve posted here, due mostly to an extreme influx of work from classes and my jobs. But that doesn’t mean I’ve given up on this blog! Rather, I have a huge number of updates, which I will only describe in short detail for now. In no particular order:

After working at the Summer School in Theoretical Computer Science at Princeton, I went to one more conference the week after the school closed out. It was the annual RANDOM/APPROX dual conference, also held at Princeton. It was extremely interesting, with riveting talks by a variety of excellent speakers. I particularly enjoyed the keynote address by David Williamson, who spoke of a new generation of approximation algorithms called “lightweight algorithms” that he believes should and will define the future of the field. I saw a lot of really interesting talks and having taken a graduate course on this last semester, I was able to at least follow a good portion of most talks.

Next, I have begun my fall semester (actually by this point, it’s more than half done..)! I ended up taking two grad courses: Advanced Complexity Theory with Sanjeev Arora and an Advanced Topics course (aka, new courses which may or may not be kept in future semesters) on Information Theory with new professor Mark Braverman. Both are extremely interesting and have gotten very challenging. I think however that complexity theory started off much harder for me since I haven’t taken the undergraduate version of this course first, but as we moved on to new material, I feel like I’m keeping up fairly well with the class. As for information theory, it started off introducing really cool ideas that were pretty straightforward to follow, but our most recent topic of communication complexity is extremely difficult for someone with no prior knowledge or experience with this. The class has a couple of PhD candidates who are very familiar with this material, so I guess that somewhat helps a bit. But it goes very fast and I need to constantly review my material. Nonetheless, it’s a ton of fun! I’m also an undergrad grader for COS 340, which is called Reasoning about Computation. It’s sort of an introduction to theoretical CS through a variety of topics including probability, hashing, algorithmic analysis, approximation algorithms, graph theory, and more. Lots of super interesting material. It’s by no means a trivial course (either to take or to grade..) but it’s an excellent jumping point for anyone interested in theory. I actually haven’t taken this course in the past due to scheduling issues, so I’m enjoying following the material as the class does it too.

We also had a Quantum Computing Day mini-workshop at Princeton. I’m hugely interested in this subj. ct although I have little formal background in it. Nonetheless, I decided to attend anyway. The keynote talk was by Scott Aaronson of MIT, a well-noted theorist in this field. The talk was, as you might expect, brilliant. I’m pretty intrigued by how matrix determinants and permanents keep popping up in so many different places. Aaronson showed the application of those concepts in dealing with fermions and bosons, which given my limited quantum physics knowledge was new to me. There was also another great talk by an IBM researcher; this one a more applied talk about actually building larger multi-qubit gates while dealing with the immensely complicated issues of maintaining the superposition. The talk was very positive and the speaker showed that IBM has made a lot of progress in pinning down some of the problems. Although many believe QC is just a fad and will never actually make it to utility, I’m optimistic to see and follow real progress being made. If for nothing else, for science.

Finally, one more big news. I was offered an internship at Google in NYC! I had interviewed with Google late last year and made it to the host matching round. However, since it was already so late, there weren’t any available projects for me. Luckily, working through a recruiter over a summer, I was able to get a headstart on the process this year and was also waived through the technical interviews since I had done them just a few months prior. I was paired up with a prospective host from the NYC office and that interview went well. Before I could hear back, I was also paired up with a host from the Mountain View office and had that interview as well. In the end, it turned out that both hosts’ reactions were positive, but I chose NYC for a variety of reasons, mostly convenience. I’m extremely excited about this opportunity and I’m eagerly waiting for the summer! The team I will be working on is Site Reliability Engineering (SRE) and my project is something to do with security.

So those are the big news items from the past few months. Hopefully, I will have time to keep this updated more regularly hereon.

EDIT: One more thing! The research that I worked on with a few other undergraduates and my professor from the summer of freshman year has finally been published and presented at IMC 2011 in Germany early in November! The paper is also now online here (I think this might be behind a paywall).

A direct link is also available here.

 
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Posted by on November 23, 2011 in Uncategorized

 

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LHC@home 2.0

I finally had a bit of spare time today, so I decided to join the LHC@home program. For those unfamiliar, it’s basically a way for the researchers at CERN’s Large Hadron Collider to utilize the processing capabilities of thousands of computers distributed across the globe to crunch out all the calculation that need to be done. As you might expect, each time beams are collided, there are several terabytes of data created per second and it is the main task of the physicists at CERN to sift through the endless volumes and look for evidence of a conjectured, yet not-yet-seen particle called the Higgs Boson. In addition, there are tons of other experiments and tests done simultaneously. So, although CERN does have the capacity of a few hundred servers dedicated to this task, it can do a great deal of good if they can utilize volunteers’ computers too.

LHC@home is similar to other programs such as SETI@home and Folding@home, which deal with the search for extraterrestrial life and do computations for protein folding, respectively. I think it’s obviously an extremely admirable task that the folks at CERN are doing and this is one (tiny) way that I’d like to pitch in.

It’s very simple to set up and use. In order to protect their data and the user’s data, all calculations are done inside a virtual machine. Although this does cause substantial slow-downs, it’s worth the risk, as corruption could create false positive (or worse, false negatives). The VM client used is VirtualBox, which is a free and very excellent. There’s a small client called BOINC that acts in facilitating the communication between the host computer and CERN’s servers, polling for new jobs, setting up the VM, running the computation, and sending back results, as well as doing host-side monitoring, etc. I’m running a laptop with two cores, so I’ve decided one core to this program, at most 90% of it, even when the computer is being used. I’ve also given it access to my GPU and at most 10GB of space on my HD. And believe me, it’s using every last bit of it. As of this writing, I’ve been running my current task for about 2.5 hrs and it’s roughly 10% done. The setup is very painless and you can just watch it go. All the information about this program (which, by the way, runs on Linux, Mac OS, and Windows) is available here.

One final note: as a volunteer, you can choose a team to work with on this. Go Team Carl Sagan!

I’ll leave you with a screenshot of how it looks on my laptop.

Look at it go!

 
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Posted by on August 10, 2011 in Uncategorized

 

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Rdio Wins

And the winner is...

After playing with both for a week, Rdio wins for me, at least for the time being. The mobile app is very clean and sleek and does the job well. It does take a bit of getting used to figure out how to do everything, but I like it and it functions pretty well. Although I do wish that there was a lesser lag time between song changes, it’s something I can live with. The real deal breaker was of course the web interface, which makes my music collection and everything I want entirely accessible at any web browser on any computer. The AIR-based desktop apps are also very slick and well put together for Windows, although I’ve had much less success with the Linux client. Oh, well.

So that’s how it will be for me. Just signed up for an Rdio Unlimited subscription this evening. I hope it remains awesome!

 
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Posted by on August 1, 2011 in Uncategorized

 

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Rdio vs. Spotify (vs. etc.)

Only one will survive..

So I’ve recently been looking into a music service to better fit my needs. I’m a huge fan on Pandora and use it all the time. It usually is exactly what I want because I like turning the music on and forgetting about it while I work or do something. But sometimes I like a bit more customization than just accepting whatever Pandora decides to throw at me. And sometimes I really, really want to listen to that particular song or album and it’s not so possible with the Pandora model. On my laptop, sure I can use Grooveshark, but it’s really on my phone when I’m out that I want that sometimes. Further, I have a bunch of files from way back when which are somewhat incomplete and all over the place and I want to be able to listen to the whole album if I want to, even though I don’t have the files downloaded. So it just makes sense for me. And it has to work on both my iPhone and Droid (so, sadly Grooveshark is out for me.. I don’t really want to jailbreak).

So, I decided to take a look at Spotify after it was launched last week. I work on Linux almost exclusively, so immediately there were some disadvantages to Spotify. Sure, there’s a beta Linux client. However, it’s not open to the free accounts because they haven’t figured out how to implement ads correctly yet (it is beta after all, so it’s understandable), which is a shame. And the Windows client runs somewhat decently in Wine, although it’s nowhere as smooth as I wish it was. Also it crashed every time I tried to run it until I realized that it was the Facebook/People tab that was breaking. So, no social features as of yet on Linux it seems!

However, regarding the music itself, I’m fairly happy. However, it definitely is harder to extrapolate from a song or artist on Spotify unfortunately. Unless you know what  you’re looking for, you’ll probably be fairly lost I think. I like that I can just play the “radio” from an artist’s page, but it keeps randomly stopping after songs! Not sure if that’s just a bug in running the Windows client on a Linux box or what, but it’s annoying. The music quality is pretty nice, nothing much to complain about there. I haven’t been able to really test out the mobile app because I’m still on a free account, which is sad because that’s really going to be the breaking point for me.

At the same time, I’ve also started my 7-day free trial with Rdio. I immediately like that there’s a web interface! Awesome, I can control it from any computer, including my CR-48, which basically has no hope of running Spotify :(. The web interface takes some getting used to, but after a day or so, I think I’m getting the hang of it. I like that I don’t need to use Facebook in order to the get the social features. It’s pretty nice and I’ve been checking out some playlists from people on there, which is a pleasant experience. The player on the left sometimes shifts when I click on a link, which is annoying, but otherwise it’s pretty well put together. The only downside I see so far is that I wish it wouldn’t take so long between songs! I’m not sure if they do any kind of prefetching the next song, but that would be something I’d really appreciate. Not fun to wait sometimes 3-5 seconds or more between songs. I also wish I could shuffle across my entire queue; that is, shuffle in songs from Artist A’s radio with Artist B’s radio too. The mobile app is also very smooth and nice to use, although I really kinda miss not being able to get album information from the player by hitting the top right icon. Actually, it sometimes just brings up a blank screen if I’m in a radio! Which is boring. Also, there’s no way for me to add a song to my collection from the player either! (You can do it from going to the History and doing it, but that’s just lame and stuff..). I like that the audio stops when a call/notification comes and then continues afterwards. I wonder if they support stopping when you set an alarm to turn off the iPod after X minutes (I know Pandora does this). Anyway, apart from that, it’s going really well so far. I still have to keep trying it out, but I’m leaning towards Rdio at this point due mostly to the web interface and ease of use in the UI. Oh and I did get the Adobe Air desktop mini-app working in Linux too, but it doesn’t seem to work when the Rdio tab is closed..

Finally, I’d just like to say that I wish there were some notion of Genres, which I can’t seem to find in either of these services. Sometimes I just care about genre and not really about the artist as much and I wish I could use this to do that. Of course, I understand that this a better use-case for Pandora, but I prefer not switching between services as much. Or maybe I just want to see the hot artists in a particular genre instead of overall. Anyway, those are my initial impressions. After this week is up, I’ll probably make a decision as to which one to pursue a paid account with.

 

 
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Posted by on July 26, 2011 in Uncategorized

 

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