Silician Sketchbook

Piled Higher and Deeper is a very QFT worthy comic strip, but this one in particular reminds me of what my macroeconomics professor said during one lecture.

Graduating? Economy going to tank? Stay in school, anyway you can.

The rationale was that job prospects, while not non-existent, were going to be harder to come by, and when the they pick up you will be in competition with younger graduates with current experience versus whatever you received 2+ years prior.

Ninja Edit: Nice follow.

As I stepped out of the subway station the other day, I think I saw a bike theft in progress. The thief was riding in the middle of the road, and narrowly missed an oncoming (blue) University Health Network bus. The victim ran past me on the sidewalk shouting.

I’m not sure how that went over seeing as how a police station is in the direction the bike was traveling, but I didn’t exactly stop to see.

Not that big a fan of bicycles myself; bike lanes here can safely accommodate only one, while sidewalks can be 4 persons wide along main avenues. Plus there’s the bonus of not having a bicycle to safeguard, although grad students get to store their bicycles in the grad common area, or potentially their lab/office.

Anonymous? In Toronto? It’s more likely than you think, at least in my building. I wonder how long those taped fliers will remain up.

Ouch. Thursdays are looking kind of grim, with a total of 6 hours of class.

So far the weather is holding up, a pretty bizarre statement to be making in January but there you go. When it gets colder, I don’t think I’ll like the late night walk to the subway station. With a number of buildings along College Street, it boggles my mind to see them unconnected.

Lunch time is probably not the best time to go to La Nave. Given the generous portions for both appetizers and entres, and the fact that the owner was the sole waiter and one of two chefs, the place strikes me as more geared to dinner.

I was in a large group, which probably aggravated the slowness, but we did have the entire restaurant, I think, so we weren’t inconveniencing anybody else. I’d expect better staffing in the evening.

The one appetizer I saw, the Salmone Affumicato, was about as large as our entre dishes. It was probably meant to be shared, in which case it would have made 2 lunch meals. At least. After finishing my Fusilli Della Nonna, I knew that I was going to be eating light later in the day.

I had to leave Simon Haykin’s lecture on cognitive radio early because I had a certain milestone to meet, and as far as milestones go, this one was the easiest one to get. No homework, quizzes, exams, or committees of professors.

That’s the positive way of looking at it. The more cynical way of perceiving JDE1000H (Ethics in Research) is that of being dragged in for a two hour talk on a late Thursday afternoon on threat of not being able to graduate. Many grad students demonstrated their disapproval by doing their homework, or digging out their laptops and surfing on the campus wireless connection.

Confidence inspiring, right? But at least they may be given the benefit of the doubt, since they were quiet about it. The same couldn’t be said about a few scattered clusters around the lecture hall.

At first I thought, naively, that it was because grad students were a cut above the superset we call undergrads. Obviously, I’ve since revised that notion. Talking in class seems to crop up whenever large groups of people are put together for something not everyone (i.e. most) wants to be there for. It’s just that my grad classes are either small and/or people take learning (or not failing and losing funding) very seriously.

Sometimes I feel that talkers are willfully sabotaging whatever class they’re in by polluting the room with the most banal conversation. The talkers themselves wouldn’t view themselves as malicious, “just bored.” And sometimes, the most damage is caused out of deliberate ignorance followed by stubborn denial.

The lecture hall in the Mining Building has the honour of being the first lecture that I’ve sat in that was built using rows of park benches with slabs of wood bolted on for a writing surface.  If it ain’t broke, don’t fix it.

Simon Haykin is old. Without any estimate whatsoever, finally seeing him at a distinguished lecture last Thursday (in the Mechanical Engineering building) was even more shocking. All I knew was that he wrote digital signal processing books - books that I managed to get by without purchasing because homework questions were posted in full online. I also inferred, from a book I saw sitting on a bookshelf during a co-op term, that he was the expert on adaptive signal processing, specifically adaptive equalizers.

In fact, the subject of his talk was an extension of something more fundamental than adaptive equalization. In his preamble while someone searched for a microphone (which he wound up not needing too much), he talked about how he got into adaptive signal processing in the first place. Adaptive meant flexibility, a robust means of getting a handle on an unknown and constantly changing environment. But adaptive signal processing, like equalizers, just means handling channel conditions. He was going for something much more ambitious: equalizing the channel, adjusting transmission and reception for optimal throughput/spectral efficiency/power, even finding unused blocks of spectrum with which to communicate in.

I was aware of software defined radio around 2002, right around the time when Haykin began a serious push for research in the area. SDR is only a means, though, and at the time was the domain of amateur radio for improving reception of narrowband voice or simple digital transmission. Cognitive radio, which was the case that he was making that afternoon, is a more general concept. How one goes about it, through hardware, software, or a mix, is implementation details.

The lecture was all about why cognitive radio (and cognitive radar), and some of the projects ongoing at his lab in McMaster University, so the whole thing bordered on non-technical. I had to leave before he got to the last part.

In his view, the holy grail of cognitive radio is to have the transceiver learn, through feedback of channel conditions and frequency use, in something almost like how humans learn, the implication being that our brains are like Bayesian systems. My interpretation is that through continuous learning, the transceiver can figure out if there are users around, or what kind of noise is corrupting which parts of the spectrum, and select modulation, bandwidth, transmit power, and forward error correction as appropriate. The US army has long been grappling with implementing such a flexible system under the JTRS.

He paraphrased Nokia’s CEO as saying that, in the next 10 years or so, wireless communications networks, 4G and beyond, will take place on cognitive radio platforms. That’s compelling, but pretty ambitious especially from a mobile terminal’s point of view. Cognitive radio will likely be achieved by more software than hardware, but overall both will be thrown at the problem in large quantities, the implication being that power consumption goes way up all else being equal. Mobile cognitive radio boosters are betting on advances in battery life (massive capacitors, miniature combustion engines or fuel cells) as well as extremely low power transistors that can deliver the same or better switching speed compared to today’s fab processes (carbon nanotubes?).

I continue to follow SDR to some extent, not because of the benefits in being flexible, but for the reasons that I think FPGA’s are cool despite being a bit clunky and generally inferior to full-custom ASIC design: both lower barriers to entry.  A combination of SDR and FPGA technology enables something like GNU Radio, which enables people to build their own ATSC tuners.  Sometimes the hardest part in doing radio signal processing is getting an infrastructure to do radio signal processing.

So anyone that has to take the TTC should know by now that there is a fare hike coming in November. While the cash fare will remain where it is at $2.75, tickets and tokens will go up $0.15 to $2.25 and the monthly Metropass price is going up $9.25 to $109. Related to the upcoming increase is attempts by the TTC to curtail token hoarding.

I haven’t been a regular TTC user for so long as to have experienced a previous fare increase, so the first question that came to mind was, Why tokens? They’re priced the same, so there should be no difference, right?

The short answer is, Tickets are easy to print. It’s not in the TTC’s best interests to honour tokens that are purchased prior to previous fare hikes, but short of upgrading every automated turnstile, there is nothing they can do. As an aside, they actually did upgrade the token infrastructure due to counterfeiting and the fact that American dimes did surprisingly well masquerading as tokens.

Tickets can’t be used for automated turnstiles, so they can be refused when presented to an operator. For those stuck with old tickets, there will come a point when the TTC will offer to refund them for their book value, or you can just pay $0.15 in addition to the old ticket [PDF] during a one-month grace period. I think that the optimal solution is to buy tokens now and refund the old tickets later.

If you happen to be a University of Toronto student, good news! A Metropass will continue to cost $87.75 for the rest of the year. For me, however, I can’t justify the cost of a Metropass - discounted or otherwise - for December since I won’t be commuting for a week, maybe two. And so I joined the ranks of would-be token hoarders.

My main entry and exit points tend to be Finch, College, and Queen’s Park stations. From my experience, tokens are only sold during rush hour. Specifically, I see them on sale at Finch around 9:30 am, and at the other stations around 5:00 pm. When I pass through on my way to class in the early afternoon, there is a red sign that says, Tokens are currently unavailable. Please buy tickets. It’s either that, or tokens are sold out (there’s a sign for that, too). Staring out the subway window at stations that have platform-level fare collector booths (Dundas and Queen stations), red signs are also present during the early afternoon.

You’ll be pleased to know that token machines at Finch, College, and Queen’s Park are either:

• Out of order
• Selling one token at a time for the cash fare price of $2.75

Where you can buy tokens in the afternoon is at Union station. I prefer Union because I’m not in a rush to get home. It adds about 10-15 minutes to my commute to class as I’m taking the long away around, but I usually take this path anyway, for reasons I may mention later.

As mentioned previously, token sales are limited to 10 tokens at a time. What isn’t mentioned is that Finch station only lets you buy 5 at a time. There are functioning token machines at Union but they only accept $10 bills and dispense 4 tokens plus change, so unless you’re in a hurry it’s better to just wait in line and buy your 10.