Qiang Yan

Research on the Human Dynamics in Mobile Communities Based on Social Identity

Through analyzing the data about the releases, comment, and forwarding of 120,000 microblog messages in a year, this paper finds out that the intervals between information releases and comment follow a power law; besides, the analysis of data in each 24 hours reveals obvious differences between microblogging and website visit, email, instant communication, and the use of mobile phone, reflecting how people use fragments of time via mobile internet technology. The paper points out the significant influence of the users activity on the intervals of information releases and thus demonstrates a positive correlation between the activity and the power exponent. The paper also points out that users activity is influenced by social identity in a positive way. The simulation results based on the social identity mechanism fit well with the actual data, which indicates that this mechanism is a reasonable way to explain peoples behavior in the mobile Internet.

Research on the interactive effects of online scores

With the popularity of online shopping, more and more consumers are making their decisions according to online reviews. However, studies on the effects of online scores produce different results, even for the same products. This study analyzes the impact of online scores from the perspective of the interaction between the different forms of online scores to provide a reasonable explanation of the inconsistency of the research results in this regard. The results of this study demonstrate that the effect of the overall score is negatively affected by the difference between the weighted score and the overall score itself. Moreover, it is also positively influenced by the difference between the overall score of one product and those of its substitutes. While considering the difference between the sub-dimensional scores and the overall score, its influence on the effect of the overall score is insignificant. This research theoretically validates the interactive effects of online scores and provides the basis for an online-score-based operation.

Impact of Bursty Human Activity Patterns on the Popularity of Online Content

The dynamics of online content popularity has attracted more and more researches in recent years. In this paper, we provide a quantitative, temporal analysis about the dynamics of online content popularity in a massive system: Sina Microblog. We use time-stamped data to investigate the impact of bursty human comment patterns on the popularity of online microblog news. Statistical results indicate that the number of news and comments exhibits an exponential growth. The strength of forwarding and comment is characterized by bursts, displaying fat-tailed distribution. In order to characterize the dynamics of popularity, we explore the distribution of the time interval Δ𝑡 between consecutive comment bursts and find that it also follows a power-law. Bursty patterns of human comment are responsible for the power-law decay of popularity. These results are well supported by both the theoretical analysis and empirical data.

Notice of Retraction The relationship between ICT investment and economic growth in China

This paper studies the relationship between information and communication technology (ICT ) investment and economic growth by applying Solow Growth Model and Granger Causal Relationship Test. The results based on the data of Chinese macroeconomic from 1996 to 2008 indicate that there is a bidirectional relationship between real gross domestic product (GDP) and ICT investment in China. On one hand, ICT investment can promote economic growth. However, when the impact of technical progress rate on economic growth is considered, the elasticity of output with respect to ICT investment is sensitive. On the other hand, as GDP of last year grows every 1 per cent, ICT investment will increase by 1.844 percentages. After fully discussed on the results, the paper aims to give a suggestion on how to make choice and adjust investment in essential factors for the growth of economic.

Social Network Analysis of Network Communities

The development of Blog presents characters of social networks. According to the analyses of networks of friends and visitors in Blog communities, the density and centrality are very low. Blog doesn’t present apparent trends of centrality. There are many isolated members in Blog communities. So currently Blog is still merely a platform for web logging. It hasn’t been a media for information dissemination.

The application of an object-oriented method in information system security evaluation

Its essential for critical systems to measure their security status. However, the research on the information system security evaluation still faces many difficulties which are caused by the complexity of the system and the inexplicit relation between the component security and the system security. In this paper, an object-oriented information system security evaluation method is introduced, the security context object model and security evaluation object model are established. These models resolve the current problems and a set of information system security evaluation tools are developed according to these works. The application of the tools is introduced and the deficiencies which need further improvement are also pointed out.

Two Fair Payment Protocols for E-Commerce Transaction

Fairness is an important property of secure electronic commerce. Most of E-payment protocols guarantee fairness by using a Trusted Third Party (TTP) or semi-trusted third party. There are few protocols without a trusted third party. Based on concurrent signature, we propose two protocols suitable for digital products transaction, one for mobile payment and the other for the transaction which has higher security requirements by customers. The most prominent character of our schemes is that there is no traditional TTP, so the network congestion can be avoided. Furthermore, the protocols satisfy fairness and some other characteristics.

Influence of Social Identity on Information Release in Microblog

Through analyzing the data about the release, comment and forwarding of 120,000 microblog messages, this paper finds out that the intervals between information release and comment observe the power law. It points out the significant influence of the users activity on the intervals of information release, and thus demonstrates the positive correlation between the activity and the power exponent. The paper also points out that users activity is influenced by social identity in a positive way. The simulation results based on the social identity mechanism fits well with the actual data, which indicates this mechanism is a reasonable way to explain peoples behavior in microblog.

On Topological Properties of Diffusion Network for Instant Messaging System

We propose and study a message diffusion network model of IM system with local-world preferential connections and acquaintance introduction mechanisms, which exist in IM system. We put forward the algorithms to generate the message diffusion network model and through simulation results we talk about the topological properties of this network. The topological properties such as degree distribution, clustering coefficient, average path length along with the community structure are simulated and analyzed. We can draw the conclusion that the degree distribution of this network obeys the power-law distribution, and this network has a short average path length and a high clustering coefficient. In a word, the simulation result shows that the message diffusion network of IM system is a complex network possessing properties of scale-free, small-world and clear community structure.

A Fair Mobile Payment Protocol

Based on concurrent signature algorithm, a fair mobile payment protocol is proposed in the paper. The protocol possesses the characters of fairness and non-repudiation. It can protect both of the consumer and merchants profits. As the electronic check is transferred by publishing a secret key, it guarantees that each participant could get the expected item at the same time. Compared to the traditional process, there are less transaction steps in our scheme. Moreover it can avoid network congestion caused by a traditional TTP and decrease the transaction centers processing pressure much. It could be used for physical goods transaction.