Thursday, September 29, 2011

Let's go back to the fountain pen

I love my Emacs (and org-mode), but there is something else about my fountain-pen. My fountain-pen is excellent for doodling and doing creative thinking. I guess the personality and non-uniformity of the handwriting adds a lot to the thinking process. Or maybe it is that handwriting requires more hand-eye coordination, or is more relaxing than typing. We are wired as analog and may process/control analog things better. I don't know what that special thing is. But for a task that requires deep thinking, I first hack at it with my pen and then move to Emacs to edit the text and digitally save/archive the text.

They should produce a tablet with a natural (high resolution, comfortable) pen input. That would save me a lot of time from having to type my writing to make it digitally available. I tried some tablets, and I was not happy with their pen support. I would be a loyal customer for an iPad like tablet with natural pen input. It could be a specialized device, it doesn't have to be a tablet-computer. I will just be happy to write on it naturally, and read papers, browse web.

Privacy through lies

A short sci-fi story by Vernor Vinge, synthetic serendipity, mentions "friends of privacy" which fabricates lies to re-achieve privacy that is violated by web-services *cough*Facebook*cough*. Here is an excerpt.
Doris Nguyen. Former homemaker. Mike eyed the youngish face. She looked almost his mom’s age, even though she was 40 years older. He searched on the name, shed collisions and obvious myths; the Friends of Privacy piled the lies so deep that sometimes it was hard to find the truth. But Doris Nguyen had no special connections in her past.
This privacy through lies idea has been explored somewhat. I have heard of a proposal where a node sends 4 different data to be processed (1 correct and 3 incorrect), so the server cannot learn what is the correct data, and the node can use only the reply to the correct data and discards the other 3 replies. I was wondering if this "privacy through lies" approach can be or is explored further.

Thursday, September 22, 2011

Trip notes from Mobicom 2011

I am attending MOBICOM'11 at Las Vegas, and mostly enjoying it. I took some notes from the talks. Here I will share my notes about a couple of talks which I found more interesting than the others.

  • SmartVNC: An effective remote computing solution for smartphones. The goal here is to improve on the usability of solutions (such as AndroidVNC) that allow accessing a remote PC from a smartphone. The problem with AndroidVNC is task-inflation: user needs to do a lot of zooming and panning and also the small keyboard is inconvenient for typing. The solution offered is to use macros to automate common user-specific tasks in AndroidVNC. The macros appear as a sidebar and the user can click a macro to perform several steps quickly. These macros are defined as hooks at the GUI level (instead of app-level or OS-level) so that they can be application-agnostic as well as robust and extensible
  • Detecting driver phone use leveraging car speakers. The goal is to block the delivery of a call or SMS for the phone in the driver seat so that the driver is not tempted to take the call. The proposed scheme is as follows. The phone sends a "beep" signal over Bluetooth to be played by the right speaker and records the round-trip time, then the phone sends a beep signal to be played by the left speaker and records the round-trip time. (Most cars at least have two channel speakers to make this scheme possible.) By using the offset round-trip times, the phone can localize itself to be in the driver seat or the passenger seat. (Yes, there are obvious/acknowledged problems with the scheme: it is not 100% robust; driver's phone sitting in the passenger seat defeats the scheme; the audible beep alerts the driver to an incoming call which may defeat the purpose.)
  • I am the antenna: accurate outdoor AP location using smartphones. The goal is to develop an app to escort a smartphone user that is connected to a WAP with a weak signal to walk towards the WAP so that he can get a stronger signal. The solution is to exploit the "body-blocking effect" to figure out the direction of the WAP. The human body blocks the RSS from the WAP significantly, so when the user's back is turned toward the WAP (that is when our body is in between the phone and the WAP) the RSS degrades significantly. In this scheme, the user fires up the app, makes a full rotation slowly, and the app tells him which direction to walk to  in order to get to the WAP. Rinse and repeat several times to locate the WAP (we could as well call this the whirling-dervish app). Unfortunately, this scheme does not work inside the buildings due to multipath effects. But it is still useful for a user outside to be able to locate the WAP in a building.

As evident from these selected talks, there is tangible excitement about smartphone research at Mobicom; but I guess the community has not completely figured out solid research directions to pursue in the smartphones area yet. In addition to the smartphone talks, there were talks on all kinds of wireless communication topics, including opportunistic routing (still kicking in 2011?), and physical and MAC layer work for wi-fi. With the help of software-defined radio platforms, the researchers can now fiddle with the wi-fi platform at granularity not possible before. As a result of this new-found flexibility, there were a couple of works which were essentially re-discovering/re-inventing some wireless sensor network MAC protocols done in 2003-2005 in the wi-fi domain.

At the end of the first day, there was an outrageous opinions session which was a lot of fun. It consisted of 8 talks with 5 minutes each. There were only two serious exploratory ideas, and the remaining 5-6 talks were in the spirit of stand-up comedy for CSE nerds. A majority of the talks were proposals (mostly tongue-in-cheek) about how to improve the review process and the conference. I like the concept a lot, and will try to include some outrageous posts of my own occassionally in this blog. By the way, here is my outrageous opinion about improving the conference experience. The keynote speaker should give $20 for each attendee as pre-compensation for their one hour. If the attendees think the talk was well-worth the $20, they will return the money back to the speaker else they keep the $20 bill as a compensation for the lost time.

During the coffee and lunch breaks I got to meet/catchup and chitchat with several colleagues. Those were probably the most fruitful time I had at the conference. We exchanged a lot of ideas, insights, stories, and gossip.  I think conferences are invaluable not because of the papers/talks, but because of these personal interactions/communications. You have to catch me in person to hear more of my Mobicom stories.

Finally, I should write a bit about Las Vegas. Vegas is home to fake Venetian canals, fake Roman statues, fake palaces, a fake Eiffel tower, fake volcanos, fake lakes, fake pirate ships, and fake hopes that fade at dawn in front of the slot machines (--while going to the registration desk at 7am the first day, I came across several people still gambling with red-eyes and frustrated faces at the casino). That said, I really liked the Bellagio fountain show; it was original and spectacular.  The conference hotel was nice, the food good. But... <bitching> the wireless in the conference was unusable the first day, and completely unavailable for me the second day. It is ironic to have these problems at a conference specializing on wireless communication. </bitching> To finish on a high note, the conference banquet was one of the best I have ever been to. It was held at the Secret Garden in the Mirage hotel. We got to see Siberian tigers, Albino lions, Albino tigers, leopards, and got to watch the dolphins' show.

Some dolphin facts. The trainers train the dolphins 6 times a day (total time spent a day is 2 hours). After 5 years of training the dolphin is able to do the tricks in typical SeaWorld show, but the trainings continue lifelong. Dolphins live around 40 years, but the trainer I talked to mentioned that he worked with some 50 year old dolphins before. The training is done mostly with positive reinforcements. If dolphins misbehave during training, the trainer stares at the dolphin's eyes and stays expressionless for 3-4 seconds. Dolphins are good at recognizing human body language (very much like dogs), and the trainers also learn to recognize dolphins' body language. Dolphins are smart, but the trainer I talked to thinks sea lions are even smarter: they can learn how to open a gate just by watching a human do it.

Sunday, September 18, 2011

Tenure advice to new faculty

A month ago, I participated at a panel as part of the new faculty orientation program of the SUNY Buffalo. There were 5 recently tenured faculty in the panel. The idea was that we would convey our tenure advice to the new faculty. I was the only one from the Engineering School, the others were mostly from Social sciences. We had 80 minutes for 5 speakers, so I expected to get 15 minutes. But, the panel was rather informal and the speaking times were not enforced. So, I got to speak as the 4th speaker for 5 minutes only. The other speakers had come with 3-4 printed pages to talk, I had keynote prepared keynote slides (which I ended up not showing with a projector). Since I feel I didn't get enough mileage out of these slides, I am sharing them here.

The panel also exposed me to some cultural differences among Social and Engineering disciplines. I didn't find their advice actionable, and probably they found my advice blunt. I won't discuss more. I am an engineer and I am proud.

Friday, September 9, 2011

Two-phase commit and beyond

In this post, we model and explore the two-phase commit protocol using TLA+. The two-phase commit protocol is practical and is used in man...