Social Network Analysis

In the last three lectures, Pro. Chan demonstrated the definition of SNA. Social Network Analysis is the study of the pattern of interaction between actors, which is simplified as SNA. In SNA, Social network is formally defined as a set of social actors, or nodes, members that are connected by one or more types of relations.

We must admit that the mathematics is used for all kinds of areas. The knowledge of matrix is used for SNA to calculate some indexes to represent the features of a social network.

The matrix used in social network analysis is called the adjacency matrix or sociomatrix. The sociomatrix is applied to represent the interaction among all actors. Of course, according to the lecture, the same social network can be explained by several means, such as the matrix, relation graph or table. I will give the example to show different explanation means represent the same social network.

1、Matrix representation:

2、Graph representation:

3、Table representation:

In the lecture, Pro. Chan gave us two indexes of centrality and prestige. The centrality and the prestige are used to elaborate the actor’s interaction, importance and other features. As Pro. Chan said, actors with centrality are those that are extensively involved in relationships with other actors. Here the relationship with other actors is emphasized. Also, actor with prestige is the one who is the recipient of extensive ties. Here the recipient is emphasized. These are used to distinguished the concepts between the centrality and the prestige. And centrality contains degree centrality, closeness centrality and betweenness centrality. Prestige contains degree prestige, proximity prestige and rank prestige.

Usually a social network’s relationship graph can be converted into a matrix. And the centrality index and the prestige index can be worked out according to the matrix and some formulas. And then we can judge the features according to these values.

As said above, interdisciplinary application is important to solve the problem.

A Social Cloud

In the social networking course, we had talked about the social cloud definition, that is, a resource and service sharing framework utilizing relationships established between members of a social network.

As we know, the networking’s best contribution is to share the resource and service. However, the coming out of cloud definition extends this sharing and optimizes the networking. The social cloud exchanges point-to-point to multi-point sharing, which improves the efficiency of the networking and enlarges the networking resource storage.

In the course, we illustrate five Social Cloud application scenarios below. And I will mainly talk about the last two scenarios.

1)      A Social Computation Cloud: an ordinary resource sharing. For example, when we have a class in a computer classroom, the teacher make a common disc send the notes to us. We can copy the notes from our own computers through common sharing file.

2)      A Social Storage Cloud: online data storage. For example, we will send our photos to Renren or Qzone. Through this method, we don’t only share our photos to our friends, but also store these photos online to release our own computer’s storage zone.

3)      An Enterprise Social Cloud: enterprise networking. For example, many corporations and other community have their own official website. By this website, they can propagate themselves and gain access to a pool resources.

However, as far as I’m concerned, the most difficult applications to distinct are the last two ones.

4)      A Social Collaborative Cloud: collaborative. This cloud is used to share information and resources within diverse user communities. For example, the SCI and EI provide the users to search for the papers.

5)      A Social Cloud for Public Science: cooperative. This cloud is primarily used to solve scientific problems of community interest. For example, some websites, especial for software engineer, provide a platform to discuss with each other about the programming problems. Another example, in some studying English websites such as Hujiang English, we can find all kinds of English studying materials, find how to study English, find some partners to study with and some articles about studying English.

So as I explain above, the first three ones are easy to distinct, but the last two ones are difficult. And we must come back to the course to talk about the different definitions between collaboration and cooperation.

As Profess Chan notes, collaboration involves the “mutual engagement of participants in a coordinated effort” to work on the task. Group members actively interact with each other on a continual basis without major interruptions by a dictator. Therefore, as 4^th social collaborative cloud, we search for the papers to research and study and we needn’t communicate with these papers’ authors. We just use these papers as a reference, an auxiliary function.

However, cooperation is characterized by a division of tasks within a group. Group members work on segments of a larger task individually and compose the separate solutions afterwards. As 5^th social cloud of public science notes, we usually can find some partners to help us solve problems or study with us together through researching and studying. We don’t regard these answers as a reference, but as a part of our researching and studying.

In conclusion, we can distinct these five applications easily.