Public opinion propagation control is one of the hot topics in contemporary social network research. With the rapid dissemination of information over the Internet, the traditional isolation and vaccination strategies ...Public opinion propagation control is one of the hot topics in contemporary social network research. With the rapid dissemination of information over the Internet, the traditional isolation and vaccination strategies can no longer achieve satisfactory results. A positive guidance technology for public opinion diffusion is urgently needed. First, based on the analysis of influence network controllability and public opinion diffusion, a positive guidance technology is proposed and a new model that supports external control is established. Second, in combination with the influence network, a public opinion propagation influence network model is designed and a public opinion control point selection algorithm(POCDNSA) is proposed. Finally, An experiment verified that this algorithm can lead to users receiving the correct guidance quickly and accurately, reducing the impact of false public opinion information; the effect of CELF is no better than that of the POCDNSA algorithm. The main reason is that the former is completely based on the diffusion cascade information contained in the training data, but does not consider the specific situation of the network structure and the diffusion of public opinion information in the closed set. thus, the effectiveness and feasibility of the algorithm is proven. The findings of this article therefore provide useful insights for the implementation of public opinion control.展开更多
Referring to the 1 248 survey data of rural population in 14 provinces of China, the influencing factors of trip time choice were analyzed. Based on the basic theory of disaggregate model and its modelling method, nin...Referring to the 1 248 survey data of rural population in 14 provinces of China, the influencing factors of trip time choice were analyzed. Based on the basic theory of disaggregate model and its modelling method, nine grades were selected as the alternatives of trip time, the variables affecting time choice and the method getting their values were determined, and a multinomial logit (MNL) model was developed. Another 1 200 trip data of rural population were selected to testify the model's validity. The result shows that the maximum absolute error of each period between calculated value and statistic is 3.6%, so MNL model has high calculation accuracy.展开更多
Aims Identifying the potential role of vegetation context(defined as the density,species identity/diversity and height of co-occurring plants)in modifying selection on floral traits is a critical step for clarifying a...Aims Identifying the potential role of vegetation context(defined as the density,species identity/diversity and height of co-occurring plants)in modifying selection on floral traits is a critical step for clarifying and predicting the floral evolutionary trajectory in complex co-flowering species competition environments.It is also helpful to understand the variation in pollinator-mediated selection.Methods We experimentally reduced vegetation height around individual plants of Spiranthes sinensis(a bumblebee-pollinated perennial orchid herb)and estimated how vegetation context modified selection on four floral traits(flowering start,plant height,corolla size and number of flowers)through female function and pollen removal over two continuous years.We randomly selected independent plants in each year.Important Findings We demonstrated that vegetation context modified selection for earlier flowering start and shorter plant height of S.sinensis.The strength of selection differed between years.In addition,selection was stronger through female function than through pollen removal.Our findings indicate the potential role of vegetation context in shaping the differentiation and diversification of flowers in angiosperms.展开更多
基金sponsored by the Natural Science Foundation of Heilongjiang Province of China under Grant No.LC2016024Natural Science Foundation of the Jiangsu Higher Education Institutions Grant No.17KJB520044 and 16KJB510024
文摘Public opinion propagation control is one of the hot topics in contemporary social network research. With the rapid dissemination of information over the Internet, the traditional isolation and vaccination strategies can no longer achieve satisfactory results. A positive guidance technology for public opinion diffusion is urgently needed. First, based on the analysis of influence network controllability and public opinion diffusion, a positive guidance technology is proposed and a new model that supports external control is established. Second, in combination with the influence network, a public opinion propagation influence network model is designed and a public opinion control point selection algorithm(POCDNSA) is proposed. Finally, An experiment verified that this algorithm can lead to users receiving the correct guidance quickly and accurately, reducing the impact of false public opinion information; the effect of CELF is no better than that of the POCDNSA algorithm. The main reason is that the former is completely based on the diffusion cascade information contained in the training data, but does not consider the specific situation of the network structure and the diffusion of public opinion information in the closed set. thus, the effectiveness and feasibility of the algorithm is proven. The findings of this article therefore provide useful insights for the implementation of public opinion control.
基金Project(51178158) supported by the National Natural Science Foundation of ChinaProjects(2010HGZY0010, 2011HGBZ0936) supported by the Fundamental Research Funds for the Central Universities of China
文摘Referring to the 1 248 survey data of rural population in 14 provinces of China, the influencing factors of trip time choice were analyzed. Based on the basic theory of disaggregate model and its modelling method, nine grades were selected as the alternatives of trip time, the variables affecting time choice and the method getting their values were determined, and a multinomial logit (MNL) model was developed. Another 1 200 trip data of rural population were selected to testify the model's validity. The result shows that the maximum absolute error of each period between calculated value and statistic is 3.6%, so MNL model has high calculation accuracy.
基金This research was supported by the Funds of the Science and Technology Department of Sichuan Province(2019YJ0393,2020YFSO309)Joint Funds of the National Natural Science Foundation of China and Yunnan Provincial Government(U1602263).
文摘Aims Identifying the potential role of vegetation context(defined as the density,species identity/diversity and height of co-occurring plants)in modifying selection on floral traits is a critical step for clarifying and predicting the floral evolutionary trajectory in complex co-flowering species competition environments.It is also helpful to understand the variation in pollinator-mediated selection.Methods We experimentally reduced vegetation height around individual plants of Spiranthes sinensis(a bumblebee-pollinated perennial orchid herb)and estimated how vegetation context modified selection on four floral traits(flowering start,plant height,corolla size and number of flowers)through female function and pollen removal over two continuous years.We randomly selected independent plants in each year.Important Findings We demonstrated that vegetation context modified selection for earlier flowering start and shorter plant height of S.sinensis.The strength of selection differed between years.In addition,selection was stronger through female function than through pollen removal.Our findings indicate the potential role of vegetation context in shaping the differentiation and diversification of flowers in angiosperms.
