Confessions of a researchaholic

January 16, 2021

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July 7, 2019


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This citadel city contains many museums, cultural heritages, and great views, all within walking distances.

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Quick sketch of a castle

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Quick sketch of a train cabin

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Quick sketch of an airplane passenger

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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.

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Interesting area around Saarbrucken Hbf

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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:

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Quick sketch of a castle ruin

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## 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

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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.

Islamic art hall

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Breath taking architecture

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

I participated the evening prayer for about 1.5 hours on Sunday May 7 2017.

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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.

Evening walk

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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.

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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.

September 26, 2014

(Really) lonely planet

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See here

December 16, 2013

Arctic desert

Filed under: Real — liyiwei @ 8:18 pm

While flying over north east Russia I saw a bizarrely beautiful landscape: some form of arctic desert rendered from the combination of desert wave geometry, icy sand material, and midnight moon lighting.

The scene cannot be captured by my camera, and also cannot be found through image or map search.

I was thinking how romantic, and yet lethal, to horse ride through that terrain.

September 28, 2013

The Klingons

Filed under: Imaginary,Real — liyiwei @ 6:47 pm
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Imagine you are a Klingon warship commander. After going through some hyper-warp to arrive at an alternative space time, you find that all Klingons are in gentle servitude to humans.

This is what I felt about the HK technology industry as a SF bay area computer scientist.

If you are a Klingon in that alternative space time, work with that commander so that you will not turn into a pussy.

September 25, 2013

How to deal with flight delays when you are already onboard

Filed under: Real — liyiwei @ 6:55 pm
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Flight delays suck. But what sucks the most is when you are already on board, so that you are trapped on that narrow seat and you cannot even walk around in a terminal.

If you are on a plane with in-flight entertainment system (stay away from those airlines/airplanes that do not even offer this basic service to all cabins) and the captain is smart enough to turn it on, start watching your favorite movies. This directly converts painful delays into extra entertainment time. At least it beats sitting there whining and worrying.

I realized this while getting delayed on board by a super typhoon a few days ago. It was a short haul flight, so the normal fly time is not even enough for an average movie. But it turns out to be enough after adding the delay. I got to watch a movie not available on Netflix.

July 26, 2013

Laptop-less in Anaheim

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I did not bring my laptop to SIGGRAPH this year to discourage myself from working inside the convention center or the hotel room.

Experimental results indicated that this motivated me to spend more time hanging out with people, which is supposed to be the main goal for a conference. I can easily schedule all events and meetings via my smart phone and tablet. (Even the tablet is probably not necessary, if I can address a few technical issues of my phone.)

I probably would have had to bring my laptop if I had to give any talks. None of the Android apps I know of can adequately author talk slides. If such apps eventually show up (and I expect they will), I would happily travel with only my phone in the future.

Eventually though, the phones will likely become powerful enough for me to work inside the hotel rooms (again).

June 14, 2013

Aromatic association of cities I have lived in more than 1 year

Filed under: Imaginary,Real — liyiwei @ 8:01 am
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They say olfactory memory is the most visceral as it is within our primitive brains.

Taipei: soil within sidewalk pavement cracks

Kaohsiung: (strong) industrial waste water

Stanford: dry grass

Palo Alto: coffee

Mountain View: swimming pool chlorine

Emerald Hills: trees

Beijing: gun powder (sulfur)

Seattle: sea-weed/salt

Hong Kong: (humid) bean curd

December 11, 2012

A gastronomic study of PhD defense

Filed under: Real — liyiwei @ 6:29 am
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HKU (Hong Kong)

No food or drink served. The candidate gives the talk, the audience asks questions, and the jury members discuss the final fate behind the door. The entire thing is over in about an hour.

Stanford (USA)

The reception food quality determines whether you pass, but do not serve coffee, as it can make jury members unnecessarily aggressive. The rest is similar to above.

INRIA (France)

The jury members meet for lunch in a nice restaurant (French, of course). The talk, QA, and jury discussion parts are similar to above. After that, a fancy reception is served (Tunisian pastry in my case). And if you, as a jury member, do not ask for trouble during the defense, you get invited to dinner in an even nicer restaurant (French, course). The entire thing takes about 11 hours.

October 2, 2012

How to adjust for jetlag

Filed under: Real — liyiwei @ 7:26 pm
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I have a very simple trick that works very well for me (I am a frequent time-zone hopper) and I believe it will work for everyone with sufficient will power.

Exercise. A lot of it.

The reasons are simple.
It is very unlikely for one to fall asleep during exercise, while very likely for one to after a long arduous one.
And it is extremely healthy, compared to alternatives (e.g. taking drugs).

All cardio-exercises will do, but my favorite is swimming; it is the least likely place to sleep within (especially if the water is not too warm) and most likely inducement for sleep afterwards (given the same amount of workout time).

July 15, 2012

How to travel

Filed under: Real — liyiwei @ 12:22 pm

(This is a random collection of thoughts for an activity that I have to do all too often and eventually learn to like, tremendously. I would hope to refine the writing gradually.)

The only tour book that I ever found worthy reading is “How to Travel With a Salmon and Other Essays” by Umberto Eco.

Tours are for the weak. Plan the itinerary yourself for maximum fun and flexibility. Have as few travel companions as possible.

Stereotypes are for the stupid.
[Vegetarians can eat more than potatoes and sauerkraut in Germany. In fact, the best vegan restaurants I have ever been to is in Munich.]

Something will go against your planning. So just relax, and be prepared.
[Should have brought my swimsuit for the unexpected detour to Japan last winter.]

Do it slow and thorough. Stay away from major tourist attractions and spend most of the time experiencing local life and culture. Pay attention to small things; both god and devil are in the details.

My most favorite routine is to barge into a local restaurant which does not seem to speak my languages, and manage to order food, interact with waiters + other customers, consume and (preferably) enjoy the food, have dessert, and pay the bill.
[Some horror stories to follow, like AAAAA intestines in France.]

July 31, 2009

Beignets in Cafe Du Monde

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I had these for breakfast in an extremely hot and humid morning in New Orleans.

Beignets in Cafe Du Monde

June 30, 2009

Hamburg travel

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This is my second trip to Germany in the last 3 months. People usually do not travel to the same place within such a short period of time, but I went both for conferences: the first one in Munich for an EG09 STAR (see here for more details), and the second one in Hamburg for an ISC09 panel.

Fortunately, Munich and Hamburg are sufficiently different to worth separate travels; in a nutshell, Munich is a more traditional Bavarian city while Hamburg a very international port.

Like Munich, Hamburg has a very good metro system, consisting of S-bahn and U-bahn. I could easily travel from the airport to my hotel via trains. Well, it is not exactly that easy, as after arriving at Dammtor Station near my hotel, I had trouble identifying the right exit for the hotel.

Fortunately, Hamburg residents are very friendly, as for at least 5 or 6 occasions during my entire trip someone volunteered to help. I guess I must look quite lost.

Being a port, Hamburg is a very watery city. On the north of the city center there are two artificial inner city lakes formed by river Alster, Aussenalster (outer Alster Lake) and Binnenalster (inner Alster Lake).

On the south of the city center is the Albe River. Near that is a new construction region named Hafencity.

Rathaus (city hall) is the landmark building of Hamburg city center, containing many shops, restaurants, and historical buildings.

Cafe Paris is one of the restaurants I visited; the vaulted ceiling with large paintings is quite beautiful.

Hamburg also has many museums. Kunsthalle, the art museum, contains two buildings, one for modern art, the other a curious mixture of classical and contemporary work. The two buildings are connected by a very unique underground tunnel.
The ethnology museum near my hotel is also very unique; I especially like the photo room, and was amazed by the ethnic similarity between Chinese and Central Asian, even though the latter is mostly nomadic (i.e. the so called barbarians in Chinese history textbooks).

I also visited the Brahms museum, and discovered that he was a Hamburg native.

Not all buildings in Hamburg are in good condition. St-Nikolai-Kirche, bombarded during WWII, served as a reminder of the wreckage of war.

Rote Flora is perhaps the most salvaged building in Hamburg, but ironically it was one of the few theaters not damaged by the war.

Unlike Munich where local Bavarian food is rampant, the restaurants in Hamburg are quite international, and it is actually not that easy to find really local tastes. Most of the restaurants I visited are quite good (e.g. the whole fish I had in Turnhalle, a restaurant converted from a gymnasium), I still wanted to try some local food. Well, the closest thing I found is in a restaurant named Filmhauskneipe (yes, near a film house); I ordered a plate of whole raw fish and veggie as suggested by the waitress to be truly German food.

For more photos I took during this travel, see here.

May 19, 2009

Living abroad gives you a creative edge

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According to this article from the Economist, living aboard gives you a creative edge.

Even without the formal study as reported in that article, this is a pretty obvious fact, at least from my personal experience. I believe the relationship between creativity and living aboard is both a cause and an effect: creative people are more likely to live aboard, and the experience of living in different places further stimulates their creativity.

Many people consider my constant moving around as being crazy, and downright counter-productive for a researcher that traditional wisdom deems to benefit from a more sedated life style. But somehow the constant traveling not only stimulates my creativity but even improves my focus. (I do not get distracted easily, but tend to lose focus when bored.)

(This post was jotted down on a flight from SEA to SFO.)

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