dsandler.org

I hadn’t planned to post anything here until after a modest redesign, but nature has forced my hand.

So there’s this hurricane. It’s kind of a big deal—currently forecast to be nearly as large as Katrina, if not her equal, and currently on a beeline for Houston/Galveston. Dr. Masters of the Weather Underground projects damage in the tens of billions of dollars as a result of a massive storm surge and damaging Category 4 winds at landfall.

I don’t expect to update dsandler.org a whole bunch; instead I’ll be posting to Twitter over the course of the next few days as E and N and I shelter in place down in Sugar Land with the in-laws. We’re likely to be slightly closer to the center of the storm, but on much higher ground, with access to more resources (larger vehicles, a generator, more people to watch the Boy, etc).

With any luck, this will be just another Adventure to tell and re-tell. “You know, you lived through a major hurricane, when you were just two months old…”

Long time, no post. Just shipped off a huge paper—one that should stand a fair chance of being accepted—and am overcome with a deep sense of relief, even closure, to go with my profound exhaustion. Finally, on to other things: new ideas full of potential and old projects, long-neglected.

You probably saw this on erinmak already, but if not, the ultrasound image below (complete with, uh, a helpful label for the disoriented) should help explain the blog silence.

Fig. 1.   5cm of forthcoming awesomeness.

This has been a part of our Big Plans since pretty much the very beginning—almost exactly ten years ago—and while it’s taken us a little longer than we’d hoped to get here, in the end I think we’re just that much more thankful and excited.

Baby-o is due in July, so everyone please wish for a cool Houston summer.

Hi. I don’t know if you remember me—I blog here occasionally.

November was particularly bad: two posts were all I had time or inclination to write. It had a little to do with big conference paper deadline, but can be chiefly attributed to the “C” Exam.

C EXAM – Deadline: 7^th semester

You must pass a private oral examination in your area of research. Each area has a formal or informal syllabus listing topics and material covered. The exam normally takes 1.5 to 2 hours. It covers both basic material, such as that from a 400-level course, and more advanced material, such a solving a problem in current research.

Your discipline/department/sorority/paramilitary outfit might refer to this cherished tradition of institutionalized hazing as quals or comps (although I suppose comps are typically written, and “quals” can sometimes refer to preliminary breadth exams).

The moniker is peculiar to Rice CS; as I understand it, the “C” is a vestige of an earlier 3-exam sequence, including “A” and “B.” (The “B” exams, mnemonically enough, were breadth exams; I have no idea what the “A” covered.) The other two exams were phased out in the 80s and 90s, as they were largely redundant with classwork and were found by grad students and advisers alike to be generally annoying. (Oh, maybe that’s what the “A” stood for.)

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Like any sufficiently diagnostic test, the qualifying exam is intended to be difficult. What makes it special, however, is that it is also intended to be unpleasant. It has been said (by my adviser, no less) that the exam doesn’t even really begin until the questioning careens into material that you are uncomfortable with. To get an idea of why this is bound to happen, let’s take a look at the entire range of topics that are fair game on your quals:

Now consider the fact that you (most likely) have a finite amount of time to prepare, and a similarly finite capacity for retaining information thus acquired. The winning strategy is to spread your studying across the entire spectrum of topics, lingering on things you’re not really familiar with (say, topics from the operating systems course you took ten years ago) to ensure even topic coverage. The histogram of your exam preparation will probably look something like the following:

Now let’s overlay the final curve: the topics actually discussed during oral questioning by your exam committee, who are free to choose areas in which they are particularly knowledgeable (or have recently researched):

Each question is likely to begin in shallow areas in which the examinee has some comfort. But, unlike a static question on a written test, the oral exam rewards a correct answer with a harder question. With no way to anticipate the course of questioning, eventually every hopeful PhD candidate will end up in deep water.

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In the end, I passed. My committee scolded me for not having deeper knowledge, but were pleased that I was able to reconstruct from first principles the things I ought to have known. (Computer scientists will note this as a classic time/space trade-off: when one resource is tight, compensate with the other.)

Now that I’m out from under this rock I have plenty to catch up on, including some research, a couple of personal software projects, and a handful of queued blog entries. In the interest of public service, I’ll close with a bit of advice for students preparing for quals. It is twofold:

1. You cannot possibly hope to study sufficiently for your quals.
2. But, by all means, try.

The funny thing about lightning is that even if it strikes twice in the same place, you don’t get any advance warning. You’re pretty much equally equipped for the second shock as the first; rationally, you can’t obsess over it.

Not so with hurricanes.

Before yesterday I hadn’t been watching local news or reading the paper, so my knowledge of the impending arrival in south Texas of Hurricane Dean was largely clinical. Where is the cone? Yes, we’re likely to be on the dirty side, even if it makes landfall at the border. Oh, but not until next week. Well, we’re likely to have more rain.

You might recall that the last time we had a hurricane hit near H-town, E and I chose early on to shelter in place. Other Houstonites didn’t, and—as you may have seen on the news—turned a greatly diminshed natural disaster into a highly amplified unnatural one.

Weather Underground 5-day forecast for Dean (latest).

So you’d think that, two years later, faced with a similar storm situation, this town’s hard-bitten residents would be composed, nonchalant, almost blasé. Oh, well, sure, there’s a hurricane, but I don’t live in the hundred-year floodplain, and my house has hurricane clips and a sturdy roof. A run on the grocery stores and gas stations isn’t warranted. We’re likely to have more rain.

My first clue that this was not the case appeared overhead as I drove on the highway yesterday. The looming traffic bulletin (and Amber-alert) signboard blinked rapidly between the following admonishments:

Anecdotal reports indicate that, indeed, lines are forming at gas stations, and supermarket shelves are starting to empty as well. Houston is whipping into a hurricane frenzy. The newspapers attempt to calmly prepare the public while local news anchors, giddy to discuss possible local death instead of recent local death, turn to their SUPER EXTREME WEATHER ASSAULT TEAM to wonder breathlessly about what might be in store and what you should do to prepare for the worst!

We are living in H-town. Hurricanetown.

E points out that all this activity could actually be a really good sign: Houstonians, once bitten, might be shy of evacuation and will hunker down until the storm has passed, armed with flashlights and fresh water and so on. They might even realize that it was the exodus, not the storm, that caused all the damage last time.

We shall see.

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[Afterword: O-Week (see also) starts today on the Rice campus, and when I go to work tomorrow morning I’m quite sure that instead of the usual anthems (Ride of the Valkyries, Back in Black, etc.) I expect to hear the residents of SRC bellowing the Scorpions’ “Rock You Like a Hurricane” from their 14th-story Klipsch stacks.]

I had an idea for a doodle just now, but couldn’t find my sketchbook on my desk.

Guess I’ve been busy.

I realize I haven’t written here in quite a while. I have a draft or two that I’ve been idly poking from time to time, like uneaten peas, but nothing really ready to go.

You’ll find I’ve spent most of my time the last few months on teaching; some of my slides are over here if you’re bored and looking for edu-tainment.

For once, E has been more prolific than I, so if you’re looking to read something, pop over there. For my part, well, expect me to have something to say—and time to say it—come late April or May.