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31.
社交网站作为互联网的新兴应用,近年来发展迅速。以Facebook和人人网为代表的社交网站现在已经拥有数以百万计的活动用户,创造了一种新的生活方式。但是社交网络快速发展的同时也带来了新的安全问题,如垃圾信息、隐私泄露、身份盗用等。文中尝试用本体来描述社交网络中的信息流动,并提供一个能够识别垃圾信息发送者的自动化解决方案。 相似文献
32.
《Digital Communications & Networks》2023,9(1):3-13
There are many problems in Social Internet of Things(IoTs), such as complex topology information, different degree of association between nodes and overlapping communities. The idea of set pair information grain computing and clustering is introduced to solve the above problems so as to accurately describe the similarity between nodes and fully explore the multi-community structure. A Set Pair Three-Way Overlapping Community Discovery Algorithm for Weighted Social Internet of Things (WSIoT-SPTOCD) is proposed. In the local network structure, which fully considers the topological information between nodes, the set pair connection degree is used to analyze the identity, difference and reverse of neighbor nodes. The similarity degree of different neighbor nodes is defined from network edge weight and node degree, and the similarity measurement method of set pair between nodes based on the local information structure is proposed. According to the number of nodes' neighbors and the connection degree of adjacent edges, the clustering intensity of nodes is defined, and an improved algorithm for initial value selection of k-means is proposed. The nodes are allocated according to the set pair similarity between nodes and different communities. Three-way community structures composed of a positive domain, boundary domain and negative domain are generated iteratively. Next, the overlapping node set is generated according to the calculation results of community node membership. Finally, experiments are carried out on artificial networks and real networks. The results show that WSIoT-SPTOCD performs well in terms of standardized mutual information, overlapping community modularity and F1. 相似文献
33.
F. Slanina 《The European Physical Journal B - Condensed Matter and Complex Systems》2008,61(2):225-240
Far-from-equilibrium models of interacting particles in one dimension
are used as a basis for modelling the stock-market
fluctuations. Particle types and their positions are interpreted as
buy and sel orders placed on a price axis in the order book. We
revisit some modifications of well-known models, starting with the
Bak-Paczuski-Shubik model. We look at the four decades old Stigler
model and investigate its variants. One of them is the simplified
version of the Genoa artificial market. The list of studied models is
completed by the models of Maslov and Daniels et al. Generically, in
all cases we
compare the return distribution, absolute return autocorrelation and
the value of the Hurst exponent. It turns out that none of the models
reproduces satisfactorily all the empirical data, but the most promising
candidates for further development are the Genoa artificial market and
the Maslov model with moderate order evaporation. 相似文献
34.
M. Porfiri E. M. Bollt D. J. Stilwell 《The European Physical Journal B - Condensed Matter and Complex Systems》2007,57(4):481-486
Opinion compromise models can give insight into how groups of individuals may either come to form
consensus or clusters of opinion groups, corresponding to parties. We consider models where randomly
selected individuals interact pairwise. If the opinions of the interacting agents are not within a certain confidence
threshold, the agents retain their own point of view. Otherwise, they constructively dialogue and smooth their
opinions. Persuasible agents are inclined to compromise with interacting individuals. Stubborn individuals slightly
modify their opinion during the interaction. Collective states for persuasible societies include extremist minorities,
which instead decline in stubborn societies. We derive a mean field approximation for the compromise model in stubborn
populations. Bifurcation and clustering analysis of this model compares favorably with Monte Carlo analysis found in
the literature. 相似文献
35.
M. Wołoszyn D. Stauffer K. Kułakowski 《The European Physical Journal B - Condensed Matter and Complex Systems》2007,57(3):331-335
We investigate the network model of community by Watts, Dodds and Newman (D.J. Watts et al., Science 296, 1302 (2002)) as a hierarchy of groups, each of 5 individuals. A homophily parameter
α controls the probability proportional to exp (-αx) of selection of neighbours
against distance x. The network nodes are endowed with spin-like variables si = ± 1,
with Ising interaction J > 0. The Glauber dynamics is used to investigate the
order-disorder transition. The transition temperature Tc is close to 3.8 for
α < 0.0 and it falls down to zero above this value. The result provides a mathematical
illustration of the social ability to a collective action via weak ties, as discussed
by Granovetter in 1973. 相似文献
36.
T. S. Evans 《The European Physical Journal B - Condensed Matter and Complex Systems》2007,56(1):65-69
Evolving networks with a constant number of edges may be
modelled using a rewiring process. These models are used to
describe many real-world processes including the evolution of
cultural artifacts such as family names, the evolution of gene
variations, and the popularity of strategies in simple
econophysics models such as the minority game. The model is
closely related to Urn models used for glasses, quantum gravity
and wealth distributions. The full mean field equation for the
degree distribution is found and its exact solution and generating
solution are given. 相似文献
37.
Recently developed concepts and techniques of analyzing complex systems provide new insight into the structure of social networks. Uncovering recurrent preferences and organizational principles in such networks is a key issue to characterize them. We investigate school friendship networks from the Add Health database. Applying threshold analysis, we find that the friendship networks do not form a single connected component through mutual strong nominations within a school, while under weaker conditions such interconnectedness is present. We extract the networks of overlapping communities at the schools (c-networks) and find that they are scale free and disassortative in contrast to the direct friendship networks, which have an exponential degree distribution and are assortative. Based on the network analysis we study the ethnic preferences in friendship selection. The clique percolation method we use reveals that when in minority, the students tend to build more densely interconnected groups of friends. We also find an asymmetry in the behavior of black minorities in a white majority as compared to that of white minorities in a black majority. 相似文献
39.
Analyses of likelihood judgments for 515 events support the idea that the perceived likelihood of an event is partly a function of affective processes. Production of affective disturbances makes events seem unlikely. Event likelihoods also are influenced by specific kinds of people and behaviors which are involved in the events. Affective determination of likelihood is stronger when actors have institutionally‐clear identities rather than institutionally‐vague identities; indeed, affect accounts for more than half of the variance in likelihoods of events within clear institutional contexts. 相似文献
40.