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Posted
Gary_Yngve said:

klenke said:

No you didn't Gary. I'm bored.

 

So, elaborate on this sentence:

"My current project is aimed at the mostly unsolved problem of controller reduction."

 

What is controller reduction?

And why is it mostly unsolved?

Suppose you have a humanoid robot. It has many joints, and it has motors on each of the joints. The robot has sensors to detect all sorts of things. How do you make the robot walk?

 

You have to figure out how to control each motor for each joint, based on the current joint positions and all the sensory input that you have.

 

Model reduction focuses on simplifying the state information so that the inputs get mapped as best as possible to the outputs (controls to observations).

 

Control reduction focuses on simplifying the control parameters (knobs/dials for the motors) so that control problems (which tend to be nonlinear and nasty) can be solved in a lower-dimensional (easier) space. Ideally a reduced controller should retain as much flexibility from the full controller and behave robustly.

 

The tricky part about control reduction is that the reduced controllers have to operate on a reduced model. One option is to do model reduction and then design a controller on the simplified model. The problem with this method is that the approximation happens at the beginning, and errors tend to compound. Ideally one would want to simultaneously simplify the model and the controller at the same time (i.e. with a closed loop between model and controller). There are esoteric mathematical methods to do this for linear systems, but extending to nonlinear systems and performing robustly is still largely open.

 

The other way to simplify control is to make control not necessary, that is, make the system inherently robust. A simple example would be a slinky. It tends to walk down stairs no matter what width/height the stairs are. More complicated examples have been studied in biomechanical literature.

 

We've explored both directions, and we've tried working with toy problems (multi-link pendulums) and with real problems (humans walking).

 

No killer results yet.

So, you're one of the assholes who's responsible for the future destruction of humanity, as illustrated in those Terminator Movies. I hate you, I hate you, I hate you....

...oh wait, they were only movies. Phew!

 

Klenke is fruit.gif again.

Posted

Gary,

Having done 6 years of grad school, I hear where you are coming from. I also think that having lots of pressure is just a part of grad school. One school of thought (not supported or bashed here, just presented) is that grad school is at least in part about finding out about how much you can do at 110%. It is a marathon. It is not easy. There are tough moments. There are moments when you want to drop out. If $$, or some idealized job post PhD is why you are doing the PhD, drop out now. It jsut gets harded. If you are truly passionate about what you are doing, the pressure is just a nuisance. If you focus on the pressure, you waste energy, become less productive and get into a negative feedback. In other words, get some perspective. It is natural to get pressure from advisors to perform. Remember that the project and the experience are why you are there. If that isn't enough, it won't be enough and that's just what it is. If your advisor is giving you a truly raw deal (be honest with yourself about this), then shop elsewhere. I know plenty of people who have swapped advisors, departments and even universities.

 

 

blah, blah, blah....

 

A few beers and some ranting usually do the trick for me, and I have a good (but sometimes difficult) relationship with my advisor. So, bigdrink.gifbigdrink.gifbigdrink.gifbigdrink.gifbigdrink.gifbigdrink.gifbigdrink.gifbigdrink.gifbigdrink.gifbigdrink.gifbigdrink.gifbigdrink.gif

 

up and get cracking!

Geek_em8.gifGeek_em8.gif

Posted
Gary_Yngve said:

skykilo said:

That sucks, man. Do you already have a project of your own? If not, then why don't you look for a new advisor? I guess I should ask about your field of research...

 

My current project is aimed at the mostly unsolved problem of controller reduction. I started the project six months ago. At least three of those months were spent doing other crap (taking a class, TAing, peer reviewing a few papers, revising a paper accepted to a conference, preparing said talk...). During the three months I had to work, I implemented balanced truncation for model reduction on linear systems, adapted spacetime optimization to work with Galerkin projections, ported a fast forward dynamics engine over to our system, read a bunch of papers, and spent countless hours debugging and tuning nonlinear constrained optimization solvers. But I haven't gotten any compelling results yet, and my advisor thinks it's because I'm not passionate about the problem. My counter is that I cannot be passionate about the problem if I'm feeling threatened to get results.

 

The new project involves using adjoint methods to solve spacetime problems faster, and it may be useful in the project that I have been working on.

 

What a tremendous contribution to humanity. The world is, officially, a better place.

Posted
glen said:

Gary,

Having done 6 years of grad school, I hear where you are coming from. I also think that having lots of pressure is just a part of grad school. One school of thought (not supported or bashed here, just presented) is that grad school is at least in part about finding out about how much you can do at 110%. It is a marathon. It is not easy. There are tough moments. There are moments when you want to drop out. If $$, or some idealized job post PhD is why you are doing the PhD, drop out now. It jsut gets harder.

 

This one thing that I don't understand about America. It seems that if you are a lawyer, doctor, professor, etc., you get paid a lot, but you are expected to put in >60 hrs a week. It seems my ideal job would be to work 30 hrs a week and get half the pay (or even a third the pay). But those jobs don't exist.

 

Am I the only one who would appreciate a job like that? How come they don't exist?

Posted

Drop out of school, cash in, and pursue this project/topic in your leisure if you are truly passionate about it.

 

Anyone talented enough get accepted into UW's PhD program in the CS department should be able to name their terms in the private sector and get away with it....

 

 

Posted

There are plenty of people with those jobs, including doctors, etc. They are in demand because they provide a necessary service and most people aren't willing to work hard enough to become proficient with that skill/knowledge set. Microeconomics at work. Academia requires a lot and caters to people who are obsessed with their work- note the absurd divorce rate amongst R1 faculty. If you want the 30 hour a week job, then think outside the box, find a niche and run with it. It is out there. But, that job is not why you should be doing a PhD. I think (without having been there) that what your advisor might have been trying to communicate is that you should rediscover the simple joy in what you do and not be afraid to be immersed in it a bit. You'll be happier and more productive. The increased productivity will generate more free time. I think it might be a bit ambitious to think that you'll be able to take 3 day weekends all the time and be successful at a research driven PhD. The academic culture in the US simply doesn't cater to that. If that is what you REALLY want, you might consider europe where there is a slightly more sane concept of a work ethic (seriously). It's not like they don't have computers, universities and climbing there.

Posted
glen said:I think it might be a bit ambitious to think that you'll be able to take 3 day weekends all the time and be successful at a research driven PhD.

 

June I did one 2-day trip.

July I did one 2-day trip.

August I did one 2-day trip and one 4-day trip.

 

I don't expect to be able to even go out every weekend.

All I know is that it seems like I am sacrificing my entire life outside of research and my advisor still is not satisfied.

 

From having talked with several people since yesterday, I've come to realize several things:

 

Many other people have had issues with my advisor.

 

We have fundamental communication barriers.

He'll be optimistic and say that I can get X done by Y time. I'll think he's crazy.

I'll be realistic and say it's not possible to get W done by Z time. He'll think I'm fatalistic.

 

He gets offended when I speak of work in terms of hours. He thinks I should be so passionate about my work that hours don't matter. I want him to appreciate and respect the sacrifices I make to put in long hours.

 

My advisor is not known for his ability to be supportive and encouraging.

Posted
Gary_Yngve said:

glen said:I think it might be a bit ambitious to think that you'll be able to take 3 day weekends all the time and be successful at a research driven PhD.

 

June I did one 2-day trip.

July I did one 2-day trip.

August I did one 2-day trip and one 4-day trip.

 

I don't expect to be able to even go out every weekend.

All I know is that it seems like I am sacrificing my entire life outside of research and my advisor still is not satisfied.

 

From having talked with several people since yesterday, I've come to realize several things:

 

Many other people have had issues with my advisor.

 

We have fundamental communication barriers.

He'll be optimistic and say that I can get X done by Y time. I'll think he's crazy.

I'll be realistic and say it's not possible to get W done by Z time. He'll think I'm fatalistic.

 

He gets offended when I speak of work in terms of hours. He thinks I should be so passionate about my work that hours don't matter. I want him to appreciate and respect the sacrifices I make to put in long hours.

 

My advisor is not known for his ability to be supportive and encouraging.

 

Damn, Gary, that sucks. The kind of shit you're dealing with is exactly why I didn't pursue my PhD in Physics. Too much Bull-Shit. (2 classes left for a Master's though)

I have a good friend finishing his PhD, and he is basically at school all the time. That sucks, man. Sorry. boxing_smiley.gif

Posted
dryad said:

I feel your pain, dude. Bummer!

 

I think I'm going to go get some bigdrink.gif and drown my sorrows tonight. Wanna come?

 

well, so much for moping about jobs... the topic of conversation quickly changed to mountains smile.gifbigdrink.gifbigdrink.gif

Posted
Gary_Yngve said:

dryad said:

I feel your pain, dude. Bummer!

 

I think I'm going to go get some bigdrink.gif and drown my sorrows tonight. Wanna come?

 

well, so much for moping about jobs... the topic of conversation quickly changed to mountains smile.gifbigdrink.gifbigdrink.gif

Yeah, we sorta had our own little Pub Club going. Nothing cheers one up like bigdrink.gif and looking at mountain porn. Good time. cool.gif

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