Just grit my teeth (and smile when possible)

“It’s an endless combat. Each morning one must put one’s capacities to the test.”
— Christine Lagarde

This screenshot is from 16:10-16:12 of YouTube video of Tokyo 1964 Olympic Marathon, when sports gear or drinks were not as scientific as they are today; when there were even runners ran bare feet.

This runner in the picture finished the race, and he was one of the best, even though not the one of the medalists.


Math olympia medal count analysis | 奥数奖牌分析

The International Mathematical Olympiad (IMO) is an annual six-problem mathematical olympiad for pre-college students younger than 20. The first IMO was held in Romania in 1959. As we will see, eastern Europeans were top performers in the IMO in the earlier years. You can find the summary data analysis in our Jupyter Notebook on GitHub.

It has since been held annually, except in 1980 (what happened in 1980?). More than 100 countries, representing over 90% of the world’s population, send teams of up to six students (under 20 years old) to compete.

Problems cover extremely difficult algebra, pre-calculus, and branches of mathematics not conventionally covered at school and often not at university level either, such as
– projective and complex geometry
– functional equations
– combinatorics
– number theory (where extensive knowledge of theorems is required).

No calculus is required. Supporters of not requiring calculus claim that this allows “more universality and creates an incentive to find elegant, deceptively simple-looking problems which nevertheless require a certain level of ingenuity”.

Rank Country Appearance Gold Silver Bronze Honorable_Mentions
0 1 China 32 147 33 6 0
1 2 United States 43 119 111 29 1
2 3 Russia 26 92 52 12 0
3 4 Hungary 57 81 160 95 10
4 5 Soviet Union 29 77 67 45 0
5 6 Romania 58 75 141 100 4
6 7 South Korea 30 70 67 27 7
7 8 Vietnam 41 59 109 70 1
8 9 Bulgaria 58 53 111 107 10
9 10 Germany 40 49 98 75 11

What is collateral | 什么是抵押 (dǐ yā)

I was writing a document on credit risk while the children were playing.  Suddenly one sneaked up behind my back and asked “what is collateral?”  什么是抵押 (dǐ yā)?

Hmm. It is something you use to secure money borrowed. That answer is not clear to children.

So, how about this:

If your aunt just bought a house with a mortgage (i.e. with money borrowed from a bank or some other places), if your aunt does not pay back the money borrowed, what will the lender do? The lender (for example, a bank) will take over the house and sell it to get the money back. The house is the collateral for the money borrowed.

Recall in Shakespeare’s play “The Merchant of Venice”, Antonio borrowed money from moneylender Shylock. If Antonio were unable to repay it at the specified date, Shylock would have taken a pound of Antonio’s flesh according to their agreement. Wow. That’s unthinkable in today’s world. But in 16th century, a pound of human flesh could be conceived as “collateral”.