How to identify influential nodes in complex networks is an essential issue in the study of network characteristics.A number of methods have been proposed to address this problem,but most of them focus on only one asp...How to identify influential nodes in complex networks is an essential issue in the study of network characteristics.A number of methods have been proposed to address this problem,but most of them focus on only one aspect.Based on the gravity model,a novel method is proposed for identifying influential nodes in terms of the local topology and the global location.This method comprehensively examines the structural hole characteristics and K-shell centrality of nodes,replaces the shortest distance with a probabilistically motivated effective distance,and fully considers the influence of nodes and their neighbors from the aspect of gravity.On eight real-world networks from different fields,the monotonicity index,susceptible-infected-recovered(SIR)model,and Kendall’s tau coefficient are used as evaluation criteria to evaluate the performance of the proposed method compared with several existing methods.The experimental results show that the proposed method is more efficient and accurate in identifying the influence of nodes and can significantly discriminate the influence of different nodes.展开更多
We study and derive the energy conditions in generalized non-local gravity, which is the modified theory of general relativity obtained by adding a term m2n-2R□-nRto the Einstein-Hilbert action. Moreover, to obtain s...We study and derive the energy conditions in generalized non-local gravity, which is the modified theory of general relativity obtained by adding a term m2n-2R□-nRto the Einstein-Hilbert action. Moreover, to obtain some insight on the meaning of the energy conditions, we illustrate the evolutions of four energy conditions with the model parameter ε for different n. By analysis we give the constraints on the model parameters ε.展开更多
“Belt and Road” is the important origin of oil import in China. Based on social network analysis and stochastic frontier gravity model, this paper studied the characteristic evolution and influence factor of oil imp...“Belt and Road” is the important origin of oil import in China. Based on social network analysis and stochastic frontier gravity model, this paper studied the characteristic evolution and influence factor of oil import network between China and “Belt and Road” countries. Then by constructing a stochastic frontier gravity model including the crude oil future price and oil importing price, it found that the international crude oil future price, the oil importing price, the political situation, the trade agreements have the effects on the China's oil import from “Belt and Road” region. It provided suggestions for improving the spatial pattern of China's petroleum trade.展开更多
The Taiji-1 satellite is a pilot satellite mission of Taiji program,which is used to verify Taiji’s key technology and also to testify the feasibility of Taiji roadmap.Taiji-1 was launched on 31 August 2019 and its d...The Taiji-1 satellite is a pilot satellite mission of Taiji program,which is used to verify Taiji’s key technology and also to testify the feasibility of Taiji roadmap.Taiji-1 was launched on 31 August 2019 and its designed mission was successfully completed.The in-orbit scientific achievements of Taiji-1 satellite in the first stage have been published and now it has entered the extended task phase.Taiji-2 will prepare all the technology needed by Taiji-3,and remove all the technical obstacles faced by Taiji-3.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61663030 and 61663032)。
文摘How to identify influential nodes in complex networks is an essential issue in the study of network characteristics.A number of methods have been proposed to address this problem,but most of them focus on only one aspect.Based on the gravity model,a novel method is proposed for identifying influential nodes in terms of the local topology and the global location.This method comprehensively examines the structural hole characteristics and K-shell centrality of nodes,replaces the shortest distance with a probabilistically motivated effective distance,and fully considers the influence of nodes and their neighbors from the aspect of gravity.On eight real-world networks from different fields,the monotonicity index,susceptible-infected-recovered(SIR)model,and Kendall’s tau coefficient are used as evaluation criteria to evaluate the performance of the proposed method compared with several existing methods.The experimental results show that the proposed method is more efficient and accurate in identifying the influence of nodes and can significantly discriminate the influence of different nodes.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11175077 and 11575075the Natural Science Foundation of Liaoning Province under Grant No L201683666
文摘We study and derive the energy conditions in generalized non-local gravity, which is the modified theory of general relativity obtained by adding a term m2n-2R□-nRto the Einstein-Hilbert action. Moreover, to obtain some insight on the meaning of the energy conditions, we illustrate the evolutions of four energy conditions with the model parameter ε for different n. By analysis we give the constraints on the model parameters ε.
基金supports from National Natural Science Foundation of China(71774087).
文摘“Belt and Road” is the important origin of oil import in China. Based on social network analysis and stochastic frontier gravity model, this paper studied the characteristic evolution and influence factor of oil import network between China and “Belt and Road” countries. Then by constructing a stochastic frontier gravity model including the crude oil future price and oil importing price, it found that the international crude oil future price, the oil importing price, the political situation, the trade agreements have the effects on the China's oil import from “Belt and Road” region. It provided suggestions for improving the spatial pattern of China's petroleum trade.
基金Supported by Strategic Priority Research Program of the Chinese Academy of Sciences(XDA15021100)。
文摘The Taiji-1 satellite is a pilot satellite mission of Taiji program,which is used to verify Taiji’s key technology and also to testify the feasibility of Taiji roadmap.Taiji-1 was launched on 31 August 2019 and its designed mission was successfully completed.The in-orbit scientific achievements of Taiji-1 satellite in the first stage have been published and now it has entered the extended task phase.Taiji-2 will prepare all the technology needed by Taiji-3,and remove all the technical obstacles faced by Taiji-3.
