Weblog patterns and human dynamics with decreasing interest

Weblog is the fourth way of network exchange after Email, BBS and MSN. Most bloggers begin to write blogs with great interest, and then their interests gradually achieve a balance with the passage of time. In order to describe the phenomenon that people's interest in something gradually decreases until it reaches a balance, we first propose the model that describes the attenuation of interest and reflects the fact that people's interest becomes more stable after a long time. We give a rigorous analysis on this model by non-homogeneous Poisson processes. Our analysis indicates that the interval distribution of arrival-time is a mixed distribution with exponential and power-law feature, that is, it is a power law with an exponential cutoff. Second, we collect blogs in ScienceNet.cn and carry on empirical studies on the interarrival time distribution. The empirical results agree well with the analytical result, obeying a special power law with the exponential cutoff, that is, a special kind of Gamma distribution. These empirical results verify the model, providing an evidence for a new class of phenomena in human dynamics. In human dynamics there are other distributions, besides power-law distributions. These findings demonstrate the variety of human behavior dynamics.Comment: 8 pages, 1 figure

Topology and correlations in structured scale-free networks

We study a recently introduced class of scale-free networks showing a high clustering coefficient and non-trivial connectivity correlations. We find that the connectivity probability distribution strongly depends on the fine details of the model. We solve exactly the case of low average connectivity, providing also exact expressions for the clustering and degree correlation functions. The model also exhibits a lack of small world properties in the whole parameters range. We discuss the physical properties of these networks in the light of the present detailed analysis.Comment: 10 pages, 9 figure

From Popularity Prediction to Ranking Online News

International audienceNews articles are an engaging type of online content that captures the attention of a significant amount of Internet users. They are particularly enjoyed by mobile users and massively spread through online social platforms. As a result, there is an increased interest in discovering the articles that will become popular among users. This objective falls under the broad scope of content popularity prediction and has direct implications in the development of new services for online advertisement and content distribution. In this paper, we address the problem of predicting the popularity of news articles based on user comments. We formulate the prediction task as a ranking problem, where the goal is not to infer the precise attention that a content will receive but to accurately rank articles based on their predicted popularity. Using data obtained from two important news sites in France and Netherlands, we analyze the ranking effectiveness of two prediction models. Our results indicate that popularity prediction methods are adequate solutions for this ranking task and could be considered as a valuable alternative for automatic online news ranking

Analyzing and Modeling Real-World Phenomena with Complex Networks: A Survey of Applications

The success of new scientific areas can be assessed by their potential for contributing to new theoretical approaches and in applications to real-world problems. Complex networks have fared extremely well in both of these aspects, with their sound theoretical basis developed over the years and with a variety of applications. In this survey, we analyze the applications of complex networks to real-world problems and data, with emphasis in representation, analysis and modeling, after an introduction to the main concepts and models. A diversity of phenomena are surveyed, which may be classified into no less than 22 areas, providing a clear indication of the impact of the field of complex networks.Comment: 103 pages, 3 figures and 7 tables. A working manuscript, suggestions are welcome

Centrality evolution of the charged-particle pseudorapidity density over a broad pseudorapidity range in Pb-Pb collisions at root s(NN)=2.76TeV

Peer reviewe

Centrosome abnormalities in giant cell tumour of bone: possible association with chromosomal instability.

Giant cell tumour of bone, a benign but potentially aggressive neoplasm, shows an increasing rate of chromosomal aneusomy that correlates with clinical course. Mechanisms that generate chromosomal instability in giant cell tumour of bone are poorly understood. One possible cause of chromosomal instability is an error in mitotic segregation due to numeric and/or functional abnormalities of centrosomes. Centrosome alteration is a common phenomenon in many cancers and has a major role in the development of chromosomal instability in cancer cells. To gain an insight into the possible mechanism for the generation of chromosomal instability in giant cell tumour of bone, we analysed 100 cases, including 57 primary nonrecurrent, 35 recurrent and 8 malignant giant cell tumour of bone cases. gamma-Tubulin immunohistochemistry was performed on tissue microarrays of 59 formalin-fixed paraffin-embedded cases, whereas pericentrin and gamma-tubulin fluorescent immunocytochemistry was carried out on 41 frozen smears. Fluorescent in situ hybridization was performed on 23 cases of pericentrin immunostained smears, allowing the simultaneous analysis of centrosomes and chromosome aberrations. Centrosome amplification was significantly higher in recurrent and malignant giant cell tumour of bones compared with nonrecurrent tumours (P<0.001). A comparison of the percentage of aneusomic cells with a normal centrosome content (4.7%) with that of aneusomic cells with centrosome amplification (6.4%) revealed no significant association between chromosome number alterations and centrosome aberrations (P=0.31). These findings indicate that centrosome alteration and frequency of aneusomy correlate with clinical behaviour; the lack of an association between centrosome amplification and chromosome number alteration suggests that alternative causative mechanisms produce genetic instability in giant cell tumour of bone