The outbreak of hotspot in social network may contain complex dynamic genesis. Using user behavior data from hotspots in social network, we study how different user groups play different roles for a hotspot topic. Fir...The outbreak of hotspot in social network may contain complex dynamic genesis. Using user behavior data from hotspots in social network, we study how different user groups play different roles for a hotspot topic. Firstly, by analyzing users' behavior records, we mine group situation that promotes the hotspot.Several major attributions in a hotspot outbreak, such as individual, peer and group triggers, are defined formally according to the view-point of social identity, social interaction, retweet depth and opinion leader. Secondly,for the problem of the uneven and sparse data in each stage of hotspot topic's life cycle, we propose a dynamic influence model based on grey system to formalize the effect of different groups. Then the process of hotspot evolution driven by distinct crowd is showed dynamically. The experimental result confirms that the model is able not only to qualify users' influence on a hotspot topic but also to predict effectively an upcoming change in a hotspot topic.展开更多
The modified shear lag model proposed recently was applied to calculate thermal residual stresses and subsequent stress distributions under tensile and compressive loadings. The expressions for the elastic moduli and ...The modified shear lag model proposed recently was applied to calculate thermal residual stresses and subsequent stress distributions under tensile and compressive loadings. The expressions for the elastic moduli and the yield strengths under tensile and compressive loadings were derived which take account of thermal residual stresses. The asymmetries in the elastic modulus and the yield strength were interpreted using the derived expressions and the obtained results of the stress calculations. The model predictions have exhibited good agreements with the experimental results and also with the other theoretical predictions展开更多
Based on risk social cognition theory and planned behavior theory, the influence factors of the public participation in the nanotechnology risk communication are analyzed,and the concept model is presented to analyze ...Based on risk social cognition theory and planned behavior theory, the influence factors of the public participation in the nanotechnology risk communication are analyzed,and the concept model is presented to analyze their relationships and functional mechanism. In the model,the risk communication behaviors are divided into two variables of the public opinion expression and information acquisition,and the subjective norm divided into the internal and external social networks. Then the questionnaire is designed so as to verify the proposed model and analyze their relationships. The survey data are analyzed using SMART PLS software. The validity analysis shows that the questionnaire has a high convergence and discriminant validity. In addition, the Cronbach'a coefficient of each item is more than 0. 70,which shows the questionnaire has a high credibility. Based on the statistical data analysis, relationships of the influence factors are obtained.Further,the influence path model of the public attitude,intention,self regulation and behavior control in the risk communication is established. According to the Bootstrap algorithm in SMART,the path coefficient and its explanation variance of each influence factor are obtained. The calculation results show that the explanation variance values are all bigger than 10% and the path is reliable.Based on the path model, the influence path and function relationships of the participation attitude, subjective norm and behavior control on the participation intention and behavior are obtained. This will provide theoretical and data supports for the risk management and strategy making of the public participation in nanotechnology risk communication.展开更多
Amyloid peptide（Aβ）oligomers are considered one of the primary causal factors for the synaptic loss characteristic of Alzheimer’s disease（AD）（Karran and De Strooper,2016）.However,Aβis generated in normal brai...Amyloid peptide（Aβ）oligomers are considered one of the primary causal factors for the synaptic loss characteristic of Alzheimer’s disease（AD）（Karran and De Strooper,2016）.However,Aβis generated in normal brains and accumulates at synaptic sites,which raises the question whether Aβplays a physiological role in synapses.展开更多
The coupling model of major influence factors such state affecting the chloride diffusion process in concrete is as environmental relative humidity, load-induced crack and stress discussed. The probability distributio...The coupling model of major influence factors such state affecting the chloride diffusion process in concrete is as environmental relative humidity, load-induced crack and stress discussed. The probability distributions of the critical chloride concentration Cc, the chloride diffusion coefficient D, and the surface chloride concentration Cs were determined based on the collected natural exposure data. And the estimation of probability of corrosion initiation considering the coupling effects of influence factors is presented. It is found that the relative humidity and curing time are the most effective factors affecting the probability of corrosion initiation before and after 10 years of exposure time. At the same exposure time, the influence of load-induced crack and stress state on the probability of corrosion initiation is obvious, in which the effect of crack is the most one展开更多
The author’s combined numerical model consisting of a third generation shallow water wave model and a 3 D tide surge model with wave dependent surface wind stress were used to study the influence of waves on tide sur...The author’s combined numerical model consisting of a third generation shallow water wave model and a 3 D tide surge model with wave dependent surface wind stress were used to study the influence of waves on tide surge motion. For the typical weather case, in this study, the magnitude and mechanism of the influence of waves on tide surges in the Bohai Sea were revealed for the first time. The results showed that although consideration of the wave dependent surface wind stresses raise slightly the traditional surface wind stress, due to the accumulated effects, the computed results are improved on the whole. Storm level maximum modulation can reach 0.4 m. The results computed by the combined model agreed well with the measured data.展开更多
Diffusion has been systematically described as the main mechanism of chloride transport in reinforced concrete（RC） structure, especially when the concrete is in a saturated state. However, the single mechanism of di...Diffusion has been systematically described as the main mechanism of chloride transport in reinforced concrete（RC） structure, especially when the concrete is in a saturated state. However, the single mechanism of diffusion is not able to describe the actual chloride ingress in the nonsaturated concrete. Instead, it is dominated by the interaction of diffusion and convection. With the synergetic effects of various factors taken into account, this study aimed to modify and develop an analytical convection- diffusion coupling model for chloride transport in nonsaturated concrete. The model was verified by simulation of laboratory tests and field measurement. The results of comparison study demonstrate that the analytical model developed in this study is efficient and accurate in predicting the chloride profiles in the nonsaturated concrete.展开更多
Streamwise Body Force Model(SBFM)could be used to simulate the force of blade on the airflow,resulting in rapid propulsion-airframe integrated simulation.However,when subjected to inlet distortion,the upstream flow fi...Streamwise Body Force Model(SBFM)could be used to simulate the force of blade on the airflow,resulting in rapid propulsion-airframe integrated simulation.However,when subjected to inlet distortion,the upstream flow field of fan stage is redistributed,which causes inaccurate prediction of fan stage performance.As inspired by the upstream influence of compressor,this paper aims to present a modification strategy for SBFM method to predict the compressor performance under circumferential inlet distortion without any knowledge of compressor geometry.Based on the linearized motion equation,the Upstream Influence Model(UIM)is introduced to predict the upstream flow field redistribution.Then the theoretical Mach number at Aerodynamic Interface Plane(AIP)position is calculated and selected to determine the corresponding body force coefficients based on the functional relationship between body force coefficients and Mach number,thus the upstream influence of compressor could be accurately quantified and the Modified Streamwise Body Force Model(MSBFM)could be established.Two studied cases are calculated with different methods and the upstream flow fields are analyzed.The prediction error of MSBFM method for compressor adiabatic efficiency is less than 3%,and the calculation efficiency is improved 20 times under the condition of ensuring computing accuracy.The MSBFM method has the potential for rapid propulsion-airframe integrated simulation.展开更多
Social media have dramatically changed the mode of information dissemination.Various models and algorithms have been developed to model information diffusion and address the influence maximization problem in complex s...Social media have dramatically changed the mode of information dissemination.Various models and algorithms have been developed to model information diffusion and address the influence maximization problem in complex social networks.However,it appears difficult for state-of-the-art models to interpret complex and reversible real interactive networks.In this paper,we propose a novel influence diffusion model,i.e.,the Operator-Based Model(OBM),by leveraging the advantages offered from the heat diffusion based model and the agent-based model.The OBM improves the performance of simulated dissemination by considering the complex user context in the operator of the heat diffusion based model.The experiment obtains a high similarity of the OBM simulated trend to the real-world diffusion process by use of the dynamic time warping method.Furthermore,a novel influence maximization algorithm,i.e.,the Global Topical Support Greedy algorithm(GTS-Greedy algorithm),is proposed corresponding to the OBM.The experimental results demonstrate its promising performance by comparing it against other classic algorithms.展开更多
With the rapid development of location-based networks, point-of-interest（POI） recommendation has become an important means to help people discover interesting and attractive locations, especially when users travel o...With the rapid development of location-based networks, point-of-interest（POI） recommendation has become an important means to help people discover interesting and attractive locations, especially when users travel out of town. However, because users only check-in interaction is highly sparse, which creates a big challenge for POI recommendation. To tackle this challenge, we propose a joint probabilistic generative model called geographical temporal social content popularity（GTSCP） to imitate user check-in activities in a process of decision making, which effectively integrates the geographical influence, temporal effect, social correlation, content information and popularity impact factors to overcome the data sparsity, especially for out-of-town users. Our proposed the GTSCP supports two recommendation scenarios in a joint model, i.e., home-town recommendation and out-of-town recommendation. Experimental results show that GTSCP achieves significantly superior recommendation quality compared to other state-of-the-art POI recommendation techniques.展开更多
Under China's innovation-driven development strategy, venture capital has become an important driving force in urban agglomeration integration and collaborative innovation. This paper uses social network analysis ...Under China's innovation-driven development strategy, venture capital has become an important driving force in urban agglomeration integration and collaborative innovation. This paper uses social network analysis to analyze spatiotemporal differences of venture capital in the Beijing-Tianjin-Hebei urban agglomeration for the period 2005–2015. A gravity model and panel data regression model are used to reveal the influencing factors on spatiotemporal differences in venture capital in the region. This study finds that there is a certain cyclical fluctuation and uneven differentiation in the venture capital network in the Beijing-Tianjin-Hebei urban agglomeration in terms of total investment, and that the three centers of venture capital(Beijing, Shijiazhuang and Tangshan) have a stimulatory effect on surrounding cities; flows of venture capital between cities display certain networking rules, but they are slow to develop and strongly centripetal; there is a strong positive correlation between levels of information infrastructure development and economic development and venture capital investment; and places with relatively underdeveloped financial environments and service industries are less able to apply the fruits of innovation and entrepreneurship and to attract funds. This study can act as a reference for the Beijing-Tianjin-Hebei urban agglomeration in building a world-class super urban agglomeration with the best innovation capabilities in China.展开更多
基金supported by National Basic Research Program of China(973 program)(Grant No.2013CB3296-06)National Natural Science Foundation of China(Grant No.61272400)+6 种基金Chongqing Innovative Team Fund for College Development Project(Grant No.KJTD201310)Chongqing Youth Innovative Talent Project(Grant No.cstc2013kjrc-qnrc40004)Ministry of Education of China and China Mobile Research Fund(Grant No.MCM20130351)Science and Technology Research Program of the Chongqing Municipal Education Committee(Grant No.KJ1500425)Wen Feng Foundation of CQUPT(Grant No.WF201403)Science and Technology on Information Transmission and Dissemination in Communication Networks Laboratory Open Subject(Grant No.ITD-U13002/KX132600009)Chongqing Graduate Research and Innovation Project(Grant No.CYS14146)
文摘The outbreak of hotspot in social network may contain complex dynamic genesis. Using user behavior data from hotspots in social network, we study how different user groups play different roles for a hotspot topic. Firstly, by analyzing users' behavior records, we mine group situation that promotes the hotspot.Several major attributions in a hotspot outbreak, such as individual, peer and group triggers, are defined formally according to the view-point of social identity, social interaction, retweet depth and opinion leader. Secondly,for the problem of the uneven and sparse data in each stage of hotspot topic's life cycle, we propose a dynamic influence model based on grey system to formalize the effect of different groups. Then the process of hotspot evolution driven by distinct crowd is showed dynamically. The experimental result confirms that the model is able not only to qualify users' influence on a hotspot topic but also to predict effectively an upcoming change in a hotspot topic.
文摘The modified shear lag model proposed recently was applied to calculate thermal residual stresses and subsequent stress distributions under tensile and compressive loadings. The expressions for the elastic moduli and the yield strengths under tensile and compressive loadings were derived which take account of thermal residual stresses. The asymmetries in the elastic modulus and the yield strength were interpreted using the derived expressions and the obtained results of the stress calculations. The model predictions have exhibited good agreements with the experimental results and also with the other theoretical predictions
基金National Social Science Foundation of China(No.14BTQ030)
文摘Based on risk social cognition theory and planned behavior theory, the influence factors of the public participation in the nanotechnology risk communication are analyzed,and the concept model is presented to analyze their relationships and functional mechanism. In the model,the risk communication behaviors are divided into two variables of the public opinion expression and information acquisition,and the subjective norm divided into the internal and external social networks. Then the questionnaire is designed so as to verify the proposed model and analyze their relationships. The survey data are analyzed using SMART PLS software. The validity analysis shows that the questionnaire has a high convergence and discriminant validity. In addition, the Cronbach'a coefficient of each item is more than 0. 70,which shows the questionnaire has a high credibility. Based on the statistical data analysis, relationships of the influence factors are obtained.Further,the influence path model of the public attitude,intention,self regulation and behavior control in the risk communication is established. According to the Bootstrap algorithm in SMART,the path coefficient and its explanation variance of each influence factor are obtained. The calculation results show that the explanation variance values are all bigger than 10% and the path is reliable.Based on the path model, the influence path and function relationships of the participation attitude, subjective norm and behavior control on the participation intention and behavior are obtained. This will provide theoretical and data supports for the risk management and strategy making of the public participation in nanotechnology risk communication.
基金supported Fundación Reina Sofía Grant PI0006-08 to LTby Ministerio de Ciencia y Tecnología(ES)grant BFU2008-04683-C02-02 to LT
文摘Amyloid peptide（Aβ）oligomers are considered one of the primary causal factors for the synaptic loss characteristic of Alzheimer’s disease（AD）（Karran and De Strooper,2016）.However,Aβis generated in normal brains and accumulates at synaptic sites,which raises the question whether Aβplays a physiological role in synapses.
基金Project(50925829) supported by the National Science Fund for Distinguished Young Scholars of ChinaProject(50908148) supported by the National Natural Science Foundation of ChinaProjects(2009-K4-23,2010-11-33) supported by the Research of Ministry of Housing and Urban Rural Development of China
文摘The coupling model of major influence factors such state affecting the chloride diffusion process in concrete is as environmental relative humidity, load-induced crack and stress discussed. The probability distributions of the critical chloride concentration Cc, the chloride diffusion coefficient D, and the surface chloride concentration Cs were determined based on the collected natural exposure data. And the estimation of probability of corrosion initiation considering the coupling effects of influence factors is presented. It is found that the relative humidity and curing time are the most effective factors affecting the probability of corrosion initiation before and after 10 years of exposure time. At the same exposure time, the influence of load-induced crack and stress state on the probability of corrosion initiation is obvious, in which the effect of crack is the most one
文摘The author’s combined numerical model consisting of a third generation shallow water wave model and a 3 D tide surge model with wave dependent surface wind stress were used to study the influence of waves on tide surge motion. For the typical weather case, in this study, the magnitude and mechanism of the influence of waves on tide surges in the Bohai Sea were revealed for the first time. The results showed that although consideration of the wave dependent surface wind stresses raise slightly the traditional surface wind stress, due to the accumulated effects, the computed results are improved on the whole. Storm level maximum modulation can reach 0.4 m. The results computed by the combined model agreed well with the measured data.
基金Funded by the National Natural Science Foundation of China(Nos.51278304,U1134209,U1434204&51422814)the National Basic Research Program(973 Program)of China(No.011-CB013604)the Technology Research and Development Program(Basic Research Project)of Shenzhen(Nos.JCYJ20120613174456685&JCYJ20130329143859418)
文摘Diffusion has been systematically described as the main mechanism of chloride transport in reinforced concrete（RC） structure, especially when the concrete is in a saturated state. However, the single mechanism of diffusion is not able to describe the actual chloride ingress in the nonsaturated concrete. Instead, it is dominated by the interaction of diffusion and convection. With the synergetic effects of various factors taken into account, this study aimed to modify and develop an analytical convection- diffusion coupling model for chloride transport in nonsaturated concrete. The model was verified by simulation of laboratory tests and field measurement. The results of comparison study demonstrate that the analytical model developed in this study is efficient and accurate in predicting the chloride profiles in the nonsaturated concrete.
基金supported by the National Natural Science Foundation of China(Nos.52176032,51976005 and 52006002)the Advanced Jet Propulsion Creativity Center,China(No.HKCX2020-02-013)+2 种基金the National Science and Technology Major Project,China(Nos.2017-II-0004-0016 and 2017-II-0005-0018)the Fundamental Research Funds for the Central Universities,Chinathe Beijing Nova Program,China。
文摘Streamwise Body Force Model(SBFM)could be used to simulate the force of blade on the airflow,resulting in rapid propulsion-airframe integrated simulation.However,when subjected to inlet distortion,the upstream flow field of fan stage is redistributed,which causes inaccurate prediction of fan stage performance.As inspired by the upstream influence of compressor,this paper aims to present a modification strategy for SBFM method to predict the compressor performance under circumferential inlet distortion without any knowledge of compressor geometry.Based on the linearized motion equation,the Upstream Influence Model(UIM)is introduced to predict the upstream flow field redistribution.Then the theoretical Mach number at Aerodynamic Interface Plane(AIP)position is calculated and selected to determine the corresponding body force coefficients based on the functional relationship between body force coefficients and Mach number,thus the upstream influence of compressor could be accurately quantified and the Modified Streamwise Body Force Model(MSBFM)could be established.Two studied cases are calculated with different methods and the upstream flow fields are analyzed.The prediction error of MSBFM method for compressor adiabatic efficiency is less than 3%,and the calculation efficiency is improved 20 times under the condition of ensuring computing accuracy.The MSBFM method has the potential for rapid propulsion-airframe integrated simulation.
文摘Social media have dramatically changed the mode of information dissemination.Various models and algorithms have been developed to model information diffusion and address the influence maximization problem in complex social networks.However,it appears difficult for state-of-the-art models to interpret complex and reversible real interactive networks.In this paper,we propose a novel influence diffusion model,i.e.,the Operator-Based Model(OBM),by leveraging the advantages offered from the heat diffusion based model and the agent-based model.The OBM improves the performance of simulated dissemination by considering the complex user context in the operator of the heat diffusion based model.The experiment obtains a high similarity of the OBM simulated trend to the real-world diffusion process by use of the dynamic time warping method.Furthermore,a novel influence maximization algorithm,i.e.,the Global Topical Support Greedy algorithm(GTS-Greedy algorithm),is proposed corresponding to the OBM.The experimental results demonstrate its promising performance by comparing it against other classic algorithms.
基金supported by the National Key Project of Scientific and Technical Supporting Programs of China(2014BAK15B01)
文摘With the rapid development of location-based networks, point-of-interest（POI） recommendation has become an important means to help people discover interesting and attractive locations, especially when users travel out of town. However, because users only check-in interaction is highly sparse, which creates a big challenge for POI recommendation. To tackle this challenge, we propose a joint probabilistic generative model called geographical temporal social content popularity（GTSCP） to imitate user check-in activities in a process of decision making, which effectively integrates the geographical influence, temporal effect, social correlation, content information and popularity impact factors to overcome the data sparsity, especially for out-of-town users. Our proposed the GTSCP supports two recommendation scenarios in a joint model, i.e., home-town recommendation and out-of-town recommendation. Experimental results show that GTSCP achieves significantly superior recommendation quality compared to other state-of-the-art POI recommendation techniques.
基金Major Program of the National Natural Science Foundation of China,No.41590842
文摘Under China's innovation-driven development strategy, venture capital has become an important driving force in urban agglomeration integration and collaborative innovation. This paper uses social network analysis to analyze spatiotemporal differences of venture capital in the Beijing-Tianjin-Hebei urban agglomeration for the period 2005–2015. A gravity model and panel data regression model are used to reveal the influencing factors on spatiotemporal differences in venture capital in the region. This study finds that there is a certain cyclical fluctuation and uneven differentiation in the venture capital network in the Beijing-Tianjin-Hebei urban agglomeration in terms of total investment, and that the three centers of venture capital(Beijing, Shijiazhuang and Tangshan) have a stimulatory effect on surrounding cities; flows of venture capital between cities display certain networking rules, but they are slow to develop and strongly centripetal; there is a strong positive correlation between levels of information infrastructure development and economic development and venture capital investment; and places with relatively underdeveloped financial environments and service industries are less able to apply the fruits of innovation and entrepreneurship and to attract funds. This study can act as a reference for the Beijing-Tianjin-Hebei urban agglomeration in building a world-class super urban agglomeration with the best innovation capabilities in China.
