Web Mining and Social Networking: Techniques and ... - tud.ttu.ee

166 7 Extracting and Analyzing Web Social NetworksFig. 7.19. Structural evolution inside of a communityThe above methods for Web structural and temporal analyses can be combined to visualizethe evolution of graph structures themselves [245]. This is most useful for Web graphs at pagegranularity in that subgraphs not dense enough to form a community can be captured. Thecharacteristics of graph structures can be observed at embryonic stage of community formationand at stage of community growth.Figure 7.19 shows evolution of the graph structure inside Japanese mobile search enginecommunities. Each of 6 panes displays the graph structure at the corresponding time. Eachpane is layed out in a “synchronized” manner, where corresponding pages (nodes) are locatedat similar positions in each pane. What has happened at each stage can be easily identified byinteractively manipulating the graphs. At the early stage, search services for mobile phones inJapan were mainly provided by startups or individuals. It can be observed that, however, aftermajor companies entered the industry, the center of the community has gradually moved tosuch companies.A lot of new words are born and die every day on the Web. It is interesting to observeand analyze dynamics of new words from linguistic perspective. To analyze the dynamics ofwords, the frequency of new words in each year is estimated. Because Japanese does not haveword separator and it is often difficult for conventional technique to accurately estimate thefrequency of new words, Support Vector Machine (SVM) is employed to extract new verbsand adjectives from the Web. Since verbs and adjectives usually inflect regularly, charactern-gram was used as features of SVM.Figure 7.20 shows evolution of new verb gugu-ru (Google in Japanese). The y-axis representsthe normalized frequency in the Web archive.It can be seen that gugu-ru has becomepopular in recent years although it was not frequently used in 1999.7.4.4 Consumer Behavior AnalysisPrevalence of blogs drastically reduced the burden for individuals to express their opinionsor impressions, and blogs have been recognized as an influential source for decision makingof individuals because blogs have agility and reality in contrast to information originated in