### 目前日期文章：200404 (7)

• Apr 30 Fri 2004 08:26
• ## Partial sum of binomial coefficients

is there any formula can calculate it directly?

• Apr 30 Fri 2004 04:10
• ## looking for the "wild lily" at northeast coast--a trip of flowe

We originally planed to drive to Miao-Li(苗栗) appreciating the tung flower (油桐花). But the distance is a little far for us and there are many tung tree in Taipei also. Therefore we change our journey that we first appreciate tung flowers in Pin-Hsi(平溪) and turn to the northeast coast to look for the "wild lily" (野百合).

• Apr 28 Wed 2004 08:29
• ## [hypercube] Circled a big round--go back to the origin again...

Last week, I tried to solve the problem by "edge isoperimetric inequality". But today I found it failed. It really depressed me...

I originally can't understand the proof of lower bound of diagnosability in hypercubes illustrated in the latest paper. So I buried my nose in calculating the relationship of degrees and size of connected component in hypercubes. After a week passing by, when I finally found out an great inequality of this two things, I found the result is exactly the same of the proof in that paper. Oh my godness! what a big round I circled these days. I would like to cry so much...

• Apr 25 Sun 2004 08:53
• ## [希臘 Greece]Our website is updated !! -- Friends Voyage in Greece

It is a wonderful website for our wonderful experience of greek tour last year (2003). If you like the atmosphere of Mediterranean or you are planning to have a trip there, we strongly recommend you to visit this website.

• Apr 23 Fri 2004 09:01
• ## [hypercube] Weekly Presentation

counting the boundary and internal edges of a connected component of hypercubes

If we obtain two values which represent the number of vertices and edges in hypercubes respectively, do we can determine the size of all possible connected components? For example, there are totlal 16 vertices and 32 edges in a 4-dimensional hypercube. Now we assume 10 vertices and 13 edges are remained in this hypercube. What are all possible cases?

• Apr 20 Tue 2004 09:05
• ## 理論大師們的幽默--如果有一天外星人攻擊地球的話...

• Apr 19 Mon 2004 09:10
• ## the Probabilistic Method--a powerful and modern tools in combinat

The "probabilistic method" is one of the most powerful and modern tools in combinatorics. The basic idea of this method is simple and elegant: In order to prove the existence of an object with a specific property, prove that a randomly chosen object satisfies that property with positive probability.