Research On Some Issues About Network Opinion Evolution

Internet is gradually becoming the new forces of social opinion propagation. Public opinion on the Internet can in large measure reflect the real condition of macroscopic consensus, so it has caused wide public concern of governments and enterprises. Recent years, it is becoming the hotspot in the domain of both social sciences and natural sciences that how public opinion on the Internet has impacted or will impact on real society and how to predict or guild the opinion effectively. However, most presented models do not consider the influence of network topology although they can explain some phenomenon occurred in the evolution of opinion well. These models can not be used to predict opinion evolution tendency.In this thesis, network opinion related issues are initially studied in pace with the demand for opinion evolution behaviors, prediction technologies and guiding mechanisms, and main contents include the influences of network topology characteristic on topic propagation and viewpoint exchange, the feature of network opinion evolution, and the prediction of opinion evolution tendency. The research work of this thesis is supported by Cultivating Fund Project for Major State Projects, University Technological Innovations Plan - 'Research on key technologies of internet opinion propagation and warning' (No. 707006). The main innovations in this thesis are outlined as following:1. The influence of network topology on propagation of topic is studied, and the effects of some kinds of networks, which include completely connected network, small world network and scale-free network, on propagation velocity of topic and stability of community consensus are mainly inspected. It is also considered that the relationship between the number and distribution characteristic of individuals holding consensus in an initial stage and the propagation process. Some helpful conclusions for opinion guidance are reached. For example, heterostructure of nodes is a deterrent to topic propagation when average degree of nodes is larger; increasing clustering coefficient of network can pick up propagation speed; there is mutual check between network topology characteristics which influence topic propagation speed.2. The influence of network topology on process of consensus exchange is researched. The definition of parameter, which represents the dispersion degree of individual consensus, and parameter used to describe the changing tendency of community opinion, are introduced. The principal conclusions include, small world property and homojunction of network can lead to enough information exchange which is benefit for reaching unified consensus; scale-free property of network can prolong the process of consensus polymerization which leads to the condition that minority will exist throughout; for networks with heterostructure higher clustering level can speed up viewpoint exchange process and shorten the time that opinion reaches at steady state.3. Some features of process of network opinion evolution are analyzed. It is found that variant stages of topic development show homogeneity in a sense. If consider this homogeneity as the inertia of evolution system, the existence of inertia should be an important basis for the prediction of evolution tendency. Further more, the hits and deployment time of hot topic have correlation, which has a bearing on the tendency of the whole series and the selection to opinion guiding methods.4. Prediction methods to the tendency of network opinion evolution are also initially studied and the way to predict network opinion tendency based on time series analysis theories is present. The results of data analysis and empirical work show that the opinion evolution tendency for short periods can be able to predict by using the method of time series analysis.