Confessions of a researchaholic

July 24, 2022

Lufthansa inflight snacks

Filed under: Real — liyiwei @ 9:26 pm
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A 1-hour flight between FRA and PRG would naturally not provide much food or drink, but I like the quality and simplicity of a bottle of water and a piece of chocolate.

July 9, 2022

EGSR in Prague

Filed under: Real — liyiwei @ 6:16 pm
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I have thoroughly enjoyed the EGSR conference and the Prague visit, and wish to have more time to explore this fantastic city.

I did not have time for drawings aside from a few very quick finger sketches on my small mobile phone, but plan to draw some from visual impression later.

July 4, 2022


Filed under: Real — liyiwei @ 11:28 am
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Upon arrival at FRA I learned that my connection flight to PRG was delayed to the next day, so I took Lufthansa’s offer for free taxi rides and hotel stay in Kronberg, which turned out to be a very nice town with a historical district (including a castle) and nice restaurants.

June 18, 2022

Pavement cubes in Prague

Filed under: Real — liyiwei @ 9:22 pm
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I noticed that sidewalks in Prague are predominantly paved by the same types of stone/concrete cubes, whose size and shape might cause (or at least less effectively prevent) the underlying layer to gradually deform over time.
I also saw a construction worker manually put one cube next to another to pave a surface.
So I guess these cubes have low enough manufacturing/material costs (via economy of scale) without too high manual labor costs (low hourly wage for construction workers and/or the curved streets are less amenable for machine construction).

January 16, 2021

Not found

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.

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