Confessions of a researchaholic

January 16, 2021

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Filed under: Real — liyiwei @ 4:03 pm
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July 7, 2019


Filed under: Real — liyiwei @ 11:11 pm
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This citadel city contains many museums, cultural heritages, and great views, all within walking distances.

July 3, 2019

Mandatory charging versus voluntary tipping

Filed under: Real — liyiwei @ 5:27 pm
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While waiting for the bus to Luxembourg I walked around the Saarbrucken Hbf area, with many interesting sights, folks, shops, and outdoor sitting areas. Like some other parts of Germany (or Europe), one has to pay to use the washrooms in the train station and department stores.

I decided not to bow to any such extortion until I found a place with an old gentleman in nice suit stood by the door holding a tip tray without mandatory charges. I happily put down the same amount that would be required in other places.


Filed under: Real — liyiwei @ 2:03 pm

## Location ##

Schloss Dagstuhl is located in Saarland near the German border with Luxembourg and France.
It is hard to reach from everywhere (2 hour train from Frankfurt airport plus 0.5 hour of taxi, even though I heard that driving from Luxembourg is about 1 hour).
But that is precisely the point: isolation can help focus and avoid distraction.
I was initially suspicious about the venue and participants of the seminar but was glad I tried it.
It was a very relaxing experience, and I got to know interesting people.

There is an old castle ruin at the top of a hill.
The main building is a newer castle with many compartments, including a small chapel, a chess room, a music room, a (pseudo) wine cellar, a dining hall, a cafeteria, and guest rooms, all connected by sometimes mysterious paths.
There is another new building with seminar rooms, guest rooms, and facilities like gym, sauna, and laundry.
I have taken some photos for visual reference:

## Time ##

There are seminars all around the year.
The one I participated took place during the July 4 week, coincidence with the company shutdown.
So the trip is like a working vacation, and it feels quite relaxing (even with the travel hassles).

## Seminars ##

Seminars are organized by volunteering individuals who file reports at the end.
Dagstuhl is basically a non-profit with support from the government and donors.
The participants pay about 50 euro per night of lodging plus other food/wine consumption outside the provided meals.

There were 3 concurrent seminars:
real VR, graph theory, and a forschungsaufenthalt (research visit) of a single person.
All participants eat together so it is kind of fun to talk with these graph theory folks (mostly mathematicians), who liked to sit together scribble about problems to solve.
During a breakfast I heard one guy asked another: do you think people would be interested in my presentation of a proof?

One guy from the graph theory seminar asked me: since you guys are doing VR, why are you still coming physically here for the seminar?
I guess we will have to keep on coming to Dagstuhl physically until we have good enough solution for VR meetings.

## Meals ##

The meals are prepared onsite, with excellent quality.
Lunches and dinners have assigned seats, randomized to maximize the number of unique peers that each participant can dine with at the same table (the happy diner problem).
I think I learned more from random discussions than the seminars.

May 18, 2018


Filed under: Real — liyiwei @ 3:40 pm

The Uber driver who took me to YUL is from Bajaia and speaks French, English, Arabic, and Berbere. It is Ramadan so he could not eat or drink from 3:30 am to 8:30 pm. I told him that I like to visit North Africa.

May 15, 2018


Filed under: Real — liyiwei @ 7:15 pm

The Uber drive that picked me up from YUL has a math degree from Concordia but could not find a job in Montreal as he could not speak French.

July 15, 2017


Filed under: Real — liyiwei @ 10:35 am

I lived in the Redmond/Seattle area between 2008 and 2011.
This is probably the most peaceful among all the places I have been to.
Below is a quick summary of the area from my memory.

I mostly rented apartments near Redmond downtown, close to work (Microsoft campus) and within walking distance to everything I ever need (bus transit center, library, groceries, restaurants, gyms, parks, cinema, etc.)

I also stayed at the Moore hotel at Seattle downtown sometimes.
It is close to some of my most favorite places in the city such as the Pike place market and the Seattle art museum.

The public transportation is great compared to California.
The light rail connects downtown and the Seatac airport, and there is a comprehensive bus system covering the entire area.

The traffic can be even worse than the Bay area though (that is really something). Avoid crossing the 520 bridge for daily commute if possible.

I have a mixed feeling about biking.
The weather (temperature, humidity, and air quality) is suitable for long distance biking, but it is still not safe given the traffic condition.
I recommend biking as an exercise but not a means for transportation.


I like the cool weather and fresh air.
It snows in the winter though. The temperature does not bother me, but a particular slushy form of ice/snow called slush, which is wet and porous, can cause (further) transportation troubles for cars, bikes, and legs.

June 3, 2017

France trip

Filed under: Real — liyiwei @ 11:47 am

I visited INRIA Nancy in December 2012 as a thesis committee member of Anass. It was cold. The weather was much better during my May 2017 visit this time, to wrap up the first 3D printing project that we started a long time ago.

The trip duration was suggested by Jonas and finalized to be between May 5 and 18 to take advantage of cheap flight ticket. I do not have to pay for the flight and hotel, but I still like to keep the prices low. It turned out that Monday May 8 is a holiday in France, so we agreed that it is better for me to stay in Paris for the weekend.

I was able to find pretty good hotel deals this time for both Paris and Nancy through

They also sent me ticket deals that could have allowed me to bypass long lines to the museums which I spent the entire weekend at due to the raining weather, but I did not carefully read and thus missed the deals. There were security checks at the museum entrances due to recent terrorist attacks.

I always like visiting religious institutions so I spent the Sunday evening in one.

The TGV ride from Paris to Nancy was pleasant and efficient as usual. I opted for Apparteo Nancy, a student dorm, instead of a hotel in the Nancy city center. The light rail in Nancy was very nice and convenient. I was embarrassed to get lost a bit on my first day to INRIA.

I sat at Jeremie’s old seat. Fortunately I could use the eduroam wifi network as other options either involve more administrative work or provide less reliable connection. The lunch vouchers are very good, because INRIA provide the best meals in the entire Nancy city (or even the Lorraine province). I like the way INRIA folks take time for and discuss research over lunch and coffee, instead of rushing through meals.

We brainstormed many ideas, and I got my hands dirty with the printers. I was amazed by the toolset Sylvain developed that included everything for 3D printing: mesh processing, a lua scripting interface, etc. The project is finally completed this time and I hope the paper will be published soon.

The only way to work inside INRIA during the weekend is by asking some Chinese postdoc to open the door for me. He took me to a nearby McDonald for lunch, which turned out to the worst possible choice in France: expensive, unhealthy, and plain bad food. I forced him to a kebab shop for the next lunch.

I tried different places for dinners, mostly low price local places (around 5 EUR). I joined their intern party which took place in a nice bar followed by a good meal in a nice Lebanese restaurant starting at 9 pm. They told me that the French usually started dinner at 7 pm.
The place Stanislav is nice as usual, especially during the warm weather.

I wish I could have tried the cheese fondue but it was only for two people.

Jonas took me to dinner the last night and we went for a sushi place so that I can judge the authenticity for him (not bad, operated by Vietnamese).

This is the first time that I took a long trip back right in front of a major paper deadline; it is not as bad as I expected even though I would not recommend.

December 14, 2014

Flight delay

Filed under: Real — liyiwei @ 7:05 pm

Dear airlines:

Passengers would be much happier if they can enjoy the in-flight entertainment uninterrupted by your announcements about delays.

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