Confessions of a researchaholic

January 19, 2017

That is the spirit!

Filed under: Real — liyiwei @ 11:05 am

I cannot wait to see these two teams play again in the NBA finals. 🙂

January 18, 2017

Paper length

Filed under: Real — liyiwei @ 11:08 am
Tags: ,

The obsession with paper length is a legacy of printed proceedings.

What matters most is readability.
I would rather spend 1 hour reading a 20-page paper than 2 hours reading a 10-page paper.

Then follows file size: the smaller the better for storage and transmission.

December 15, 2016

Altruism is the ultimate form of selfishness

Filed under: Real — liyiwei @ 12:30 am

Recently, a student told me that he is not all that motivated for his own first-authored project. And yet he asked to help other projects because he could get extra papers without doing much work.

If I am not sufficiently motivated in a project, I am unlikely to contribute enough to help my team succeed. Even if it does, other team members will remember me as a free rider. I might as well do something else.

November 24, 2016

Throw in 10 pages of user study and you get yourself a CHI paper

Filed under: Real — liyiwei @ 6:58 pm

November 17, 2016

Jun Xing PhD defense

Filed under: Real — liyiwei @ 2:07 am

I have been the shadow adviser for several PhD students before.
Jun is my first official PhD student, who just successfully defended his thesis.

Do not expect me to completely turn to the light side though. I still prefer external advisees, and will continue to be very selective in taking internal students; there are only two so far.

November 12, 2016

Basis cases

Filed under: Real — liyiwei @ 8:38 pm
Tags: ,

Back in the good old days when I was working as a GPU architect in NVIDIA, we had suites of tests for various stages of GPU development: architecture, RTL, driver, real chips, etc.

Ogtest, consisting of tests written in OpenGL, can be applied to all stages. Each test is written to be as compact as possible, the tests are ordered from simple to complex, and collectively they cover the entire target space (e.g. all applications to run on the target GPU).

For example, the first test is to draw a flat colored triangle, the next is a textured triangle, and the next is called son-of-the-textured-triangle (with two textures instead of just one, if I remember correctly).
I then went on to add a test called daughter-of-the-textured-triangle (I am all in for gender equality) which consists of two textures but exercised a different path through the texturing and shading units (if I remember correctly).

I like to think of these as the basis test cases for the entire target space, analogous to basis vectors in linear algebra.

This applies to all research and development projects. Instead of jumping to debug full-scale applications, it can help to design a set of basis cases first. The process can clarify our thinking, and help us debug and explore algorithm/implementation issues. The basis cases can even be part of the analysis section of a research paper.

October 31, 2016

References for MS/PhD applications

Filed under: Real — liyiwei @ 9:15 pm

Overall, I like to help you as much as possible.

If you are applying for a MS/course program, the reference letters probably are not very important, as the top US schools (to my knowledge) mainly look at your statistics, like GPA, ranking, GRE, etc.
To put it more bluntly, MS program is a source of revenue for them.
For this, all you need is to have obtained top grades in the courses I have taught.
However, I can only comment your specific course performance but not extrapolate, e.g. from basic programming (a class you took with me) to machine learning (a class you did not take with me).

If you are applying for a PhD/research program, you need to have at least some good publications. Any decent professors/researchers know that good grades do not imply good research potential. (I am not aware of any rigorous study, but I think the two are weakly positively correlated at best). Thus, I will write letters only for those who have published top research papers or built good industry products with me, as otherwise the recommendation is likely moot.

October 30, 2016

US election 2016

Filed under: Real — liyiwei @ 8:13 pm

All people are not equal across all space and time in human history.

Such inequality used to be determined by hereditary traits such as race and sex, but more by merits such as character and capability nowadays.

This election has been driven by a large negative force from those who want to revert to the old days of hereditary discrimination and protectionism.
But doing so is only going to make everyone much worse off.

I have cast my vote that can (albeit very slightly) reduce the chance of this disastrous outcome.

[after the election]

Like many people, I was initially very surprised by the upset.
But surprises are part of my day jobs: failed experiments, rejected grants, negative reviews, etc.
I am excited to see convention wisdom turned upside down.
A fully functional democracy can work things out even with a non-conventional president.
Maybe history will show that is exactly what we need.

October 27, 2016

Halloween costume

Filed under: Real — liyiwei @ 9:43 pm

I decided to be Elliot Alderson, so that I do not have to do anything extra.

OK Hong Kong is too warm for a hoodie, but I wear that while in the bay area.

October 21, 2016

Research riddle

Filed under: Real — liyiwei @ 6:45 pm

Identify the common relationships between the following pairs of papers.

Discrete element textures, SIGGRAPH 2011
Vignette: interactive texture design and manipulation with freeform gestures for pen-and-ink illustration, CHI 2012

Dynamic element textures, SIGGRAPH 2013
Draco: bringing life to illustrations with kinetic textures, CHI 2014

Motion field texture synthesis, SIGGRAPH Asia 2009
Energy Brushes: interactive tools for illustrating stylized elemental dynamics, UIST 2016

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