  The relationship of friends in social networks can be strong or weak. Some
research works have shown that a close relationship between friends conducts
good community structure. Based on this result, we propose an effective method
in detecting community structure in social networks based on the closeness of
relations among neighbors. This method calculates the gravity between each
neighbor node to core nodes, then makes judgement if the node should be
classified in the community or not, and finally form the process of community
detection. The experimental results show that the proposed method can mine the
social structure efficiently with a low computational complexity
