Sth about Powers of a Matrix

After talking about this issue last lecture with you in front of the blackboard and being prepared for any feedback (although none given - -), I understood the issue more to details than before.

Since my understand of what the powers of the Matrix donates and why it is was all presented in the class so in this blog I want to talk about some other thinking about it.

In X, there are some elements showed as "-", which means undefined. But when doing calculations of X, "-" is calculated just as  "0". So at first there were some seconds when I was puzzled why use such a strange sign instead of defining it as zero directly? Indeed that's more like a matrix than that with some "-"s, isn't it?

Not until when I tried to explain the issus I explained to you last lecture that I understood it better. In my opinion, elements in X not only shows whether two points are combined, but also suggest a corresponding relation. That's about what I said before in the class, when and only when two elements of the same location in the row vector and column vector has the same non-zero value can we get a non-zero result. So maybe I shouldn't say that "-" is calculated just as "0". "-" still has its own calculation function, and it just can't contribute new variables to the result.

Still in X, all the meaningful and non-zero elements have the same power: 1. Why is it?
I have three ideas about this question.

1. The first idea comes from the first glance at the matrix. Just as the old thinking in the binary system: 1 represents "there be" and 0 represents "there not be". And a point doesn't need to reach itself so it's "-", undefined.

2. The second idea comes from the conclusion of the meaning of the powers of a matrix. 1 shows two points are combined. And what's more, since in X, we only have one step to take, so if we can and we want to reach another point, we can only go for it directly, no other ways. So the elements can't have other values than 1.

3. The last idea comes from the process I tried to explain the reason of the meaning for the powers of a matrix. Since all the calculable elements have the power of 1, all the variables added to the result of an element in X.^2 is 1. How many 1s are added here corresponds to the number of middle points here. Only with such defination can we have the wanted effects in X.^2, or X.^n (n>=2).

That's some of my thinking about the powers of a matrix in SNA.
Hoping for more ideas ~~~

Individual Work and Group Work

The last class of last Tuesday had brought us an interesting activity, where we can experience both individual work and group work on a task and then really feel the differences.

-- Answers to Class Activity One

Definition:

A Social Cloud is a resource and service sharing framework utilizing relationships established between members of a social network.

Application:

A Social Computation Cloud
A Social Storage Cloud
A Social Collaborative Cloud
A Social Cloud for Public Science
An Enterprise Social Cloud

-- Answers to Class Activity Two
Exactly the same as that of Activity One

-- What was the epistemic aims in (1) Class Activity One (individual work) and (2) Class Activity Two (group work)?
-- Is there any differences in terms of individual and group epistemic cognition, how?
 
I thint the epistemic aims in Activity One is to come up with an idea of a problem. It about a improvement from "not know" to "know" or "not solved" to "solved", even from "there not be" to "there be". Also, it's all about completing something with one's own work. There is no others' idea, and no others' guide, either. While Activity Two is to come up with an idea from a group of ideas. Here, others' idea can certainly be a kind of help, or guide, also, can be a kind of interupt (when you find others holding a different idea from yours).

-- How did you approach to the problem individually and in group, respectively? Is there any differences in the processes involved?

As Activity One is something about individual work, I did it all by myself, with my own idea. And when doing it in group, since all of us had already held a certain idea, so the process changed a lot. We took a glance at all our answers, found the most held idea, and then discussed it first. Group discussion can be an opportunity to find different idea, even we had the same answer to the questions in this activity, we can also get new idea of how such answer came about.

There is a little pity that all of us held a common idea in group work, so I haven't experienced the process of ideas being changed by others. But in the project of this course we can experience more group work. I'm looking forward it ~~~