Confessions of a researchaholic

October 29, 2009


Filed under: Real — liyiwei @ 6:27 pm
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I watched this movie a few nights ago. It is about Genghis Khan’s early life, between his childhood and his unification of the Mongolian tribes. I guess people might expect or want to see his more (in)famous later life for conquering the entire world, but that belongs to a (rumored) sequel. I actually prefer to watch his early life as that part is less well known.

The movie is unique in several aspects. The dialogues are primarily in Mongolian with occasional Mandarin. Mongolian sounds interesting, kind of halfway between Mandarin and Korean, even though the Mongolian spoken by most actors in the movie are not very authentic. (I have probably heard more authentic ones from real Mongols in Beijing airport.) The scenery is gorgeous, and in fact so difficult to film that the director has been thinking about cutting short or even canceling the sequels. The plot is a bit loose and incoherent, but the style nicely (and maybe coincidentally) reflects the mythological nature of Genghis Khan’s early life and the nomadic Mongolian life style around that time.

The Mongols also possess certain historical fascination to me. The Chinese history books, authored primarily by the Han Chinese, naturally debased the Mongols (and any other ethnic minorities) as barbarians and describe their histories mainly as window dressings of the greatness of the Middle Kingdom. As far as I could recall I have never read a sufficiently accurate and non-biased recount of the Mongolian history. (The history text books authored by the Nationalist government in Taiwan around my time did not even recognize Mongol as an independent country.) This is sad, as the Mongols have made major impacts to world history and geography during their great conquering around the thirteenth century, however short living their empire was. As analyzed by certain historians (e.g. see False Economy: A Surprising Economic History of the World, by Alan Beattie), the Mongols could be responsible for the formation of dictatorship/authoritarian countries like Russia, Iran, and China, which were actually more liberal than the Europeans prior to the Mongolian invasion.

October 24, 2009

Schrödinger’s cat

Filed under: Imaginary,Real — liyiwei @ 4:06 pm

When I was a kid I have been deeply fascinated by theoretical physics (to the point that I was propelled to pick up college level calculus and physics around age 15), and a recent article in Economist reminded me of one of the questions I had in my mind a long time ago.

Here it is. If someone opens the box containing Schordinger’s cat without my knowledge, what will the cat’s existence to me? Is it still a quantum superposition (i.e. the cat is dead and alive simultaneously), or it will collapse into a definite probabilistic state (i.e. the cat is either dead or alive with a certain probability, but not both)?

I never ended up pursuing theoretical physics because I opted for a more practical major in college that would allow me to “hack” things, so I still do not know the answer to that old question. But now I think for all practical reasons, the cat (or any macroscopic object) is very unlikely to be in a true quantum superposition for a very simple reason: it is simply too macroscopic to be devoid of quantum disturbances that act as probes to collapse the quantum states. Thus, for all practical purposes, the intriguing situation is unlikely to exist; the cat is either dead or alive, but not both.

Growing old does not necessarily make one wiser, but likely more pragmatic.

October 21, 2009

How to enforce rigour

Filed under: Real — liyiwei @ 12:15 pm
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An excellent post by Sylvain Lefebvre on how to enforce rigor in research.

October 6, 2009

How to read papers

Filed under: Real — liyiwei @ 5:36 pm
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I assume you already know why you should read papers (if you are doing research). If not, ask your adviser(s) or senior members of your group. If they tell you that you do not need to read papers, or if you could manage to conduct research without reading papers, please drop me a note. I would love to learn how you manage that.

The primary goal of reading paper is to know “what” other people are doing, not “how” they do it (this is only the secondary goal). Mistaking the secondary as the primary is probably the most common misconception I have seen. It is true that eventually you will have to figure how the algorithms work, etc, but that is after you know what you want to do, the primary goal stated above.

For me, reading papers is like reading gossip or fashion magazines (I got plenty exposure to these thanks to my wife); I want to know what my friends and colleagues are up to, what the trends and future directions are, and what kind of topics would interest me as a potential research project.

As a corollary, try to maximize the marginal return of the time you spent on reading papers. Maybe there are people out there who are smart enough to be able to read all the papers, but for mortals like me, the suggestion is as follows. Instead of attempting to read the papers entirely (a common mistake by rookies), try to spend as little time as possible on each paper to pick up the gist or key ideas. For most papers, I usually spend only a few minutes (and sometimes seconds) going through only the abstract, introduction, images, and videos. The latter two are a blessing for graphics researchers; more often than not it is possible to know a paper by simply watching the video or flipping through the images. In particular, if the video (or the talk slides) is sufficiently informative, I could sometimes bypass the paper entirely. (So the best way to read a paper is actually not reading at all.) Plus, even for papers I have read entirely, I usually only remember the main points eventually.

Finally, if you visualize the distribution of papers you read in the ambient space of all papers, it should form a “T” shape, i.e. you should read board enough to cover all major topics in your field (the horizontal part of T), and you should be an expert on at least one subfield (the vertical part of T) that presumably will be where you publish.

Research advice

Filed under: Real — liyiwei @ 4:25 pm
Tags: ,

After already collaborating (and publishing) with a double-digit number of students, I finally realized that I have been given answers and advices to the same set questions over and over again. So I think it is time to write them down.

For the benefit of my readers and myself, I will try to keep these posts as terse as possible without losing completeness (similar to the guideline for SIGGRAPH paper length). I will mark all my research advice posts under the advice tag.

Voice mail preview

Filed under: Real — liyiwei @ 10:04 am

My mom left a message in my phone, and below is the transcript of the “voice mail preview” via automatic speech analysis. The technology is developed by a highly regarded company. But unfortunately, converting a speech in Mandarin into English proves futile.

Voice Mail Preview (confidence is low):

Lady I sat.

But I think you need solutions if you call me back and hi counting packaging Wei you do windshield wanted after please again my P password I have to dial in and if you are you today application accesses handle it would be okay with you I got an account shown again and tell you oh I’m John shoes and KJ net slash if and making this is hundred chiaki okay okay bye bye.

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