USER-GENERATED CONTENT (UGC) ENCOUNTERED ENTERPRISE-GENERATED CONTENT (EGC): QUANTIFYING THE IMPACT OF EGC ON THE PROPAGATION OF NEGATIVE UGC

The impact of user-generated content (UGC), especially negative UGC on enterprises is well recognized. From the perspective of enterprises, different strategies of enterprise-generated content (EGC) have also been adapted to response to the unexpected UGC, but few studies have investigated the influence of such strategies on the UGC propagation. This research examines which strategy on the negative UGC propagation is optimal by proposing EGC-UGC interaction model. It aims to understand the interaction between UGC and EGC in the context of the social network. Using a simulation analysis method to measure the effect of such EGC factors as the first time of issuing EGC, EGC quantity and interactive frequency on the UGC propagation, the study finds that interactive frequency is the most key factor in defending against negative UGC propagation. This research further explores the effect of different strategy combination referring those three factors on the two types of negative UGC propagation based on deviation distance. The results present two optimal strategies for the two types of negative UGC propagation, respectively. Overall, these findings offer some unique implication for UGC management, information diffusion model of competitive information coexisting

Identification of Opinion Spammers using Reviewer Reputation and Clustering Analysis

Online reviews have increasingly become a very important resource before making a purchasing decisions. Unfortunately, malicious sellers try to game the system by hiring a person or team (which is called spammers) to fabricate fake reviews to improve their reputation.Existing methods mainly take the problem as a general binary classification or focus on some heuristic rules. However, supervised learning methods relies heavily on a large number of labeled examples of deceptive and truthful opinions by domain experts, and most of features mentioned in the heuristic strategy ignore the characteristic of the group organization among spammers. In this paper, an effective method of identifying opinion spammers is proposed. Firstly, suspected spammers are detected by means of unsupervised learning based on reviewer’s reputation. We believe that the reviewer’s reputation has a direct relation with the quality of reviews. Generally, review written by user with lower reputation, shows lower quality and higher possibility to be fake. Therefore, the model assigns reputation score to each reviewer wherein the content based factors and activeness of reviewers are employed efficiently. On basis of all suspected spammers, k-center clustering algorithm is performed to further spot the spammers based on the observation of burst of review release time. Experimental results on Amazon’s dataset are encouraging and indicate that our approach poses high accuracy and recall, and good performance is achieved

Influence of long-range cation order on relaxor properties of doped Pb(Mg1/3Nb2/3)O3 ceramics

The 1:1 B-site cation order in Pb(Mg1/3Nb2/3)O3 relaxor ferroelectric ceramics was significantly enhanced by doping of minor amounts of La3+, Sc3+, or W6+ (less than 3 at. %) combined with a slow cooling procedure. Transmission electron microscopy examination confirmed the size increase of the cation-ordered regions embedded in a disordered matrix in the samples that were slowly cooled after sintering. The average cation ordering parameter (S) determined from x-ray diffraction data in these partially ordered samples was about 0.3–0.4. The ferroelectric properties and dielectric relaxation were compared in partially ordered and disordered (S=0) samples with the same composition. It was found that typical relaxor behavior was preserved in partially ordered ceramics. Furthermore, the temperature and diffuseness of the characteristic relaxor permittivity peak and the parameters of dielectric relaxation (in particular, the distribution of relaxation times and the Vogel-Fulcher freezing temperature) were practically independent of S. In contrast, the diffuseness of the phase transition from the ferroelectric phase (induced by external electric field) to the ergodic relaxor phase appeared to be much larger in the disordered samples than in the partially ordered ones (this diffuseness was assessed using pyroelectric current and ferroelectric hysteresis loops). These results suggest that cation ordering did not influence the behavior of polar nanoregions which are responsible for the dielectric response in the ergodic relaxor phase but significantly influenced the ferroelectric phase transition. The results are interpreted in terms of different types of polar regions in the disordered matrix and cation-ordered domains

Haplotype diversity and genetic similarity among populations of the Eastern honey bee from Himalaya-Southwest China and Nepal (Hymenoptera: Apidae)

International audienceAbstractApis cerana Fabricius, the principle mainland species of Apis s.str. in Asia, remains an amalgamation of populations with considerable variation and regionally specialized morphotypes. In this study, populations of A. cerana were evaluated from the Himalayan region and areas in southwestern China as well as from neighboring Nepal based on a 97-bp-long fragment of mtDNA spanning the COI and COII genes. A total of 14 haplotypes were detected among the 58 sampled sequences, including 11 new haplotypes and 3 haplotypes previously reported from Chinese and Japanese populations of A. cerana. Analysis of these haplotypes and additional previously reported haplotypes from the Oriental region using neighbor-joining methods support a clustering of the Oriental haplotypes relative to southern India, but was unable to resolve with great support affinities within the branch. The network analysis revealed a mostly radiant genetic pattern, whereby most haplotypes were directly connected to one particular haplotype, Japan1. Our results indicate that the previously identified morphoclusters may reflect regional, ecological specialization among otherwise unrelated genetic lineages rather than a single, shared history