Skip to main content

Posts

Hasenschule: A girl who invented a matrix.

I have a fun to teach C. Six months ago, she had a problem of one digit plus and minus. She often cried in my class. But now she can calculate three digits plus and minus. One day, she was solving a question shown in Figure 1. Figure 1. The question. I expected the answer as shown in Figure 2. If she could do it, I would be happy. Figure 2. Expected answer. While I looked other students, she worked on the problem. I just walked next to her, and what I saw was, my god, a matrix! (Figure 3) Figure 3. A matrix is invented. I asked her, ``Wait a moment! Did you do this alone?'' she answered me ``Yes, I did. It is not correct?'' It doesn't matter. The correctness of the calculation doesn't matter. I was astonished that she organized the answer like this. I could see two vectors in the original question, but both numbers are written in the horizontal direction. She rearranged one of a set of horizontal numbers to the vertical direction and put the ...

Hasenschule: Was bedeutet das? Bitte erklären das mir. What does it mean? Please explain me that. (3)

Case A. A. was studying geometry. That time, A Rechtschreibung (spelling) teacher Ms M watched her. The question was how many cross point (Schnittpunkt) of the three lines (Gerade) in the figure. In the question figure, the cross points are emphasized, but, she could not answer the question. Ms M asked me to help her. As usual, I asked her (A.), ``Could you please explain me what is a line? (Bitte erklären mir was ist Gerade.)'' She answered me ``A line is a line. (Gerade ist Gerade.)'' Well, that's true, but there is no information. ``How the school taught you. A line has an end? Or a line has no end?'' ``A line has no end.'' I see, so I know she learned the difference between line, half line (ray), and segment at her school. ``OK, then what is Schnittpunkt?'' I actually didn't know what is a Schnittpunkt. She answered, ``I don't know.'' So we asked other teacher, what is a Schnittpunkt. It is a cross point of two lines....

Hasenschule: Was bedeutet das? Bitte erklären das mir. What does it mean? Please explain me that. (2)

Case S. S. was solving a multiplication problem. One piece of black bread costs 2.9 Euro. How much is the each of Anzahl (quantity) : 2, 4, 6, and 8? Figure 1 show the problem. Figure 1. Case S. question. She answered the first question of Anzahl (quantity) 2 case as 5.8 Euro. (As shown in the figure, some European countries including Germany use the comma as the decimal point. In this text I use period as the decimal point.) However, next question, she calculated 2.9 x 5.8 for the quantity 4 case. I asked her why she did it. (In Figure 2, you can see the trace of that.) She believe she should do that and she explained something. However, I didn't understand it. So, I said, I don't understand your explanation. It turns out she also doesn't know why she did that. So I wrote Figure 2, then I explained if we have four pieces of bread, 4 x 2.9 would be the answer. Figure 2. How to calculate the price? First she fixed my figure to put the shadow on the left side of...

Hasenschule: Was bedeutet das? Bitte erklären das mir. What does it mean? Please explain me that. (1)

When my students asked me a question, I usually answerd the following: ``Was bedeutet das? Bitte erklëren das mir. (What does it mean? Could you please explain me that?)'' I continue as: ``Mathe ist eine Sprache. Es gibt eine Bedeutung. (Math is a language. There is usually some meaning.)'' When I asked my students to explain the meaning of the question, they sometimes answer me, ``You are a teacher, you explain me.'' Well, that's true. But, I want to know they understand the question. I also want to teach them how to explain something. Therefore, I ask them, ``What does the question mean?'', ``Is it true?'', ``Please explain that why.'' Sometimes some students cried saying, ``You didn't teach me an answer.'' or ``You didn't help me. Help me, please.'' I was thinking, ``The answer is not so important. I want to you to learn how to learn by yourself. This is a practice. I wish soon you don't need my ...

Web hosting story: Could you google your company's advertisement?

This is a story of web hosting on an Internet provider. It didn't work unfortunately in my case. I use Alice since you can quite it in a few months time span instead of  a two years contract. I signed up ``comfort'' that has a better service even the hardware is the same with extra 15 Euro/month. I liked it since I never need to wait the service operator. The quality of the operator was good. That was around 2009. After that, O2 bought Alice. This time, I could not manage the ftp connection. I can connect to the server, but the connection only kept a few seconds. It was unstable. I changed client software, I looked forum, I changed operating system, I changed other connection point... I spent around eight hours in three days. I called the service, but it turned out, the operator didn't know what was ftp. Another operator showed up, he seems also no clue about what I was asking. He told me this night shift could not handle the request, we will call back in the mor...

Authors in a Markov matrix Part 2 (11): Appendix

Appendix A: Unicode and Python 2.7.x This time I develop python programs. I use python 2.7.3. Handling Unicode was needed to process web pages, not only for Japanese and German web pages, but also for English pages. Because some of the English authors have accent characters.  In the early development stage, I was bothered UnicodeDecodeError and UnicodeEncodeError exceptions. Here I will explain what they are, why they raised, and how to handle them. How the Unicode encodes characters? As far as I understand, Unicode uses two maps to encode characters. This depends on how you understand this coding system. I hadn't known this until I worked on this research. My understanding was that there are many kind of Unicode, like UTF-8, UTF-16, UTF-32. But this was my misunderstanding. UTF-8 is how to encode the Unicode data and Unicode is an encoding system how to encode characters. UTF-8 is one of the mapping methods, or transformation formats and UTF-8 is not Unicode (Universal ch...

Authors in a Markov matrix Part 2 (10) Experimental results: Which author do people find most inspiring?

Conclusion To find out that which author do people find most inspiring, we used the link structure of Wikipedia. First we extracted the link structure of Wikipedia and create the adjacency matrix, then we apply an eigenanalysis method, which is also called PageRank, to answer the first question. We showed the results of German, English, and Japanese authors.  We also compared the same category (authors), but between the different data source, i.e., different language Wikipedia. We can see the interesting similarity and also difference.  Personally, one of the authors was surprised me that Winston Churchill and Issac Newton have a high ranking score. He didn't know Winston Churchill is the Nobel Prize winner of the literature. Computational literature Recently, I use a mathematical approach or an information scientific approach to understand literature and languages. This approach has a huge limitation, but on the other hand, it gives me some measureable values. BrenĂ©...