Homepage of Yutaka Nishiyama(西山豊)


巨大組体操の
危険性を検証する


笹子トンネルは
設計ミス、施工ミス

 Boomerang by Prof Yutaka Nishiyama at river side of Yodo in 1992


Boomerang Instructions in 70 Languages
 Last update 11 Oct 2018

Plus online magazine of Cambrigde University, UK

Mysterious Number 6174, Mar 2006
Most popular article!
Winning Odds, June 2010 (C) Unit Fractions, Feb 2012 (C)
50 Visions of Mathematics
May 2014
Circles rolling on circles
May 2014

            Topics   ( Old Topics since Jan 2011 )
No.281 [エレガント]  『数学セミナー』 2018年9月号の「エレガントな解答をもとむ」欄に解答・講評が掲載されました(8月10日)。

No.280 [災害] 笹子トンネル事故で甲府検察審査会へ審査申立書を提出しました。<ここ>(8月8日)。

No.279 [エレガント]  『数学セミナー』 2018年6月号の「エレガントな解答をもとむ」欄に出題しました(5月12日)。

No.278 [組体操] 運動会のピラミッド「膝立ち危険」 専門家が注意喚起、中国新聞、2018年5月3日<ここ>(5月3日)。

← World University Ranking Top 139/200 registered "Mysterious Number 6174."

              54 Mathematics in Daily Life  (J):Japanese, (S):Spanish, (C):Chinese, (Wi):Wikipedia

1. Boomerang (J)(Wi)(R)
2. Five Petals (J)
3. Fixed Point (J)(Wi)
4. Boolean Algebra (J)
5. Stroboscope (J)
6. Egg Shape (J) (S)
7. Barcodes (J)
8. Harmonic Series (J)
9. Moebius (J)
10. Hexaflexagon (J)(Wi)
11. Inside out (J)
12. Miura Folding (J)
13. Sepak Takraw (J)(P)
14. Increasing of Area (J)
15. 6174 (J)(Wi)
16. Palindrome 196 (J) (Wi)
17. Oldham Coupling (J)
18. Planimeter (J)
19. Sicherman Dice (J)
20. Montmort Theory (J)
21. Random Number (J)
22. Root 2 (J)
23. Cycloid (J)
24. Machin and Pi (J)
25. Burnside Lem. (J)(Q)
26. Heptadecagon (J)
27. Sudoku (J)
28. Odd and Even (J)
29. Curve & Straight (J)
30. Finger Count (J) (S)
31. Writing Direction (J)
32. Penney Ante (J)(C)(Wi)
33. Flex Geometry (J)
34. Van Aubel (J)(Wi)
35. Red or Black (J)
36. Similarity Trans (J)
37. 52 Cycling Cards (J)
38. Straw Flute (J)
39. Minor Keys (J)
40. Benham's Top (J)
41. 2000 Yen (J)(Wi)
42. Unit Fraction (J)(C)
43. Card Shuffle (J)
44. Kruskal Count (J)(F)
45. Triangle 3 Colors (J) (Q)
46. Fullerene C60 (J)
47. Random dots, Regular
48. 19 faces of HexFlex
49. Wheel Question (Q)(J)
50. 1/998001(J)
51. Zeta function (J)
52. Sepak based C60 (J)
53. 100-cells calc (J)(F
54. Pyaramid (J) (1) (2) (Wi)

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