U-curve model
https://gyazo.com/4af6ff261bf5d9399b1a3158120c28c6
https://gyazo.com/129e670cbcd595e8a68c897ca5c039ec
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This page is auto-translated from /nishio/U曲線モデル using DeepL. If you looks something interesting but the auto-translated English is not good enough to understand it, feel free to let me know at @nishio_en. I'm very happy to spread my thought to non-Japanese readers.