以Web of Science中SCI-E、SSCI数据库1991～2010年的数据作为统计来源,对其进行计量分析,根据时间序列,将数字图书馆的发展分为4个时间段,运用关键词共现分析法,分析每一时间段的研究重点。同时对文献的合著作者采用社会网络分析法,离...以Web of Science中SCI-E、SSCI数据库1991～2010年的数据作为统计来源,对其进行计量分析,根据时间序列,将数字图书馆的发展分为4个时间段,运用关键词共现分析法,分析每一时间段的研究重点。同时对文献的合著作者采用社会网络分析法,离析出数字图书馆研究中的主要学术合作群体及其研究的热点问题,多角度揭示数字图书馆研究的发展趋势和方向。展开更多
Under the special background of China, the cooperative innovation between different government-industry-university-research institutes plays an increasingly important role in the agricultural field. However, the exist...Under the special background of China, the cooperative innovation between different government-industry-university-research institutes plays an increasingly important role in the agricultural field. However, the existing literature has paid little attention to it. Considering the cooperation patents, published in the agriculture field stemming from the Full-text Database of China Patents as the study object, the spatial and institutional attribute of the authors as the data source, and by combining the social network and spatial econometrics analysis, this paper analyzes the structure evolution characteristics of cooperative innovation networks of agricultural government-industry-university-research institute in the city level of China in 1985–2014, based on the triple helix theory, with the influence factors discussed. This shows that, 1) since 1985, China's agricultural innovation level has been substantially increased, but the development degree of the cooperative innovation network is low, and the patent cooperation mainly relies on authors in the same unit; 2) enterprises play a leading role in the agricultural cooperative innovation. The effect of the government and hybrid organizations driven by the government is not obvious; 3) the cooperative innovation in the province and city dominates, and a multi-pole pattern has been formed. The cooperative innovation network structure evolves from a single helix empty core and double helix multi core to a double helix hierarchical network; 4) the city's science, education funding and personnel investment are key factors determining the agricultural cooperative innovation, while the agricultural development of the city presents slight negative impacts on it. The spatial mismatch of supply and demand is present in the technical cooperative innovation of China's agriculture. Therefore, the science enhancement and education investment to big agricultural provinces should be promptly implemented.展开更多
In primate species with social systems consisting of one-male breeding units （OMUs）, resident male takeover represents a major challenge to individual reproductive success and mating strategies. The golden snub-nose...In primate species with social systems consisting of one-male breeding units （OMUs）, resident male takeover represents a major challenge to individual reproductive success and mating strategies. The golden snub-nosed monkey （Rhinopithecus roxellana） is characterized by large multilevel societies （MLS） comprised of several OMUs and all-male units （AMUs）; however, the factors and mechanisms associated with resident male takeover, which offer important insight into primate reproduction and social strategies, are still poorly understood. Based on 5-year monitoring data from a free-ranging herd of golden monkeys from the Qinling Mountains in China, we categorized three phases of an OMU, that is, a rising phase, developing phase, and declining phase. The rising and declining phases were unstable periods in which male takeover in an OMU might occur. Factors causing takeover, such as leader male rank, fighting ability, reproduction rate, and affiliation （proximity, allogrooming）, were analyzed for males and females and for different OMUs. Results indicated that the new resident male＇s fighting ability was lower than that of the former resident male in 23 cases. After replacement, the rank order of the new resident male significantly declined. Females involved in a takeover increased their distance from the resident male and decreased mating frequency during the three months prior to takeover. Females with infants under one-year-old had a marked effect on the specific time of takeover occurrence. These results suggested that female choice was the main factor deciding whether a takeover attempt was successful. Furthermore, rather than male conflict, females more often initiated and affected takeover and outcome, implying that the social status and competitive ability of the males played lesser roles during takeover.展开更多
Despite that existing data sharing systems in online social networks （OSNs） propose to encrypt data before sharing, the multiparty access control of encrypted data has become a challenging issue. In this paper, we p...Despite that existing data sharing systems in online social networks （OSNs） propose to encrypt data before sharing, the multiparty access control of encrypted data has become a challenging issue. In this paper, we propose a secure data sharing scheme in 0SNs based on ciphertext-policy attribute- based proxy re-encryption and secret sharing. In order to protect users＇ sensitive data, our scheme allows users to customize access policies of their data and then outsource encrypted data to the OSNs service provider. Our scheme presents a multiparty access control model, which enables the disseminator to update the access policy of ciphertext if their attributes satisfy the existing access policy. Further, we present a partial decryption construction in which the computation overhead of user is largely reduced by delegating most of the decryption operations to the OSNs service provider. We also provide checkability on the results returned from the OSNs service provider to guarantee the correctness of partial decrypted ciphertext. Moreover, our scheme presents an efficient attribute revocation method that achieves both forward and backward secrecy. The security and performance analysis results indicate that the proposed scheme is secure and efficient in OSNs.展开更多
文摘以Web of Science中SCI-E、SSCI数据库1991～2010年的数据作为统计来源,对其进行计量分析,根据时间序列,将数字图书馆的发展分为4个时间段,运用关键词共现分析法,分析每一时间段的研究重点。同时对文献的合著作者采用社会网络分析法,离析出数字图书馆研究中的主要学术合作群体及其研究的热点问题,多角度揭示数字图书馆研究的发展趋势和方向。
基金Under the auspices of National Natural Science Foundation of China(No.41471105,41430637,41701197)Program for Innovative Research Team(in Science and Technology)in University of Henan Province(No.16IRTSTHN012)+1 种基金Key Project of the Humanities and Social Sciences Research Base in Ministry of Education(No.15JJDZONGHE008)China Postdoctoral Science Foundation(No.2013M531667,2014T70672)
文摘Under the special background of China, the cooperative innovation between different government-industry-university-research institutes plays an increasingly important role in the agricultural field. However, the existing literature has paid little attention to it. Considering the cooperation patents, published in the agriculture field stemming from the Full-text Database of China Patents as the study object, the spatial and institutional attribute of the authors as the data source, and by combining the social network and spatial econometrics analysis, this paper analyzes the structure evolution characteristics of cooperative innovation networks of agricultural government-industry-university-research institute in the city level of China in 1985–2014, based on the triple helix theory, with the influence factors discussed. This shows that, 1) since 1985, China's agricultural innovation level has been substantially increased, but the development degree of the cooperative innovation network is low, and the patent cooperation mainly relies on authors in the same unit; 2) enterprises play a leading role in the agricultural cooperative innovation. The effect of the government and hybrid organizations driven by the government is not obvious; 3) the cooperative innovation in the province and city dominates, and a multi-pole pattern has been formed. The cooperative innovation network structure evolves from a single helix empty core and double helix multi core to a double helix hierarchical network; 4) the city's science, education funding and personnel investment are key factors determining the agricultural cooperative innovation, while the agricultural development of the city presents slight negative impacts on it. The spatial mismatch of supply and demand is present in the technical cooperative innovation of China's agriculture. Therefore, the science enhancement and education investment to big agricultural provinces should be promptly implemented.
基金funded by the National Science Foundation of China(31470455,31622053,31730104)National Key Program of Research and Development,Ministry of Science and Technology of China(2016YFC0503200)Northwest University Graduate Innovation and Creativity Funds(YZZ17156)
文摘In primate species with social systems consisting of one-male breeding units （OMUs）, resident male takeover represents a major challenge to individual reproductive success and mating strategies. The golden snub-nosed monkey （Rhinopithecus roxellana） is characterized by large multilevel societies （MLS） comprised of several OMUs and all-male units （AMUs）; however, the factors and mechanisms associated with resident male takeover, which offer important insight into primate reproduction and social strategies, are still poorly understood. Based on 5-year monitoring data from a free-ranging herd of golden monkeys from the Qinling Mountains in China, we categorized three phases of an OMU, that is, a rising phase, developing phase, and declining phase. The rising and declining phases were unstable periods in which male takeover in an OMU might occur. Factors causing takeover, such as leader male rank, fighting ability, reproduction rate, and affiliation （proximity, allogrooming）, were analyzed for males and females and for different OMUs. Results indicated that the new resident male＇s fighting ability was lower than that of the former resident male in 23 cases. After replacement, the rank order of the new resident male significantly declined. Females involved in a takeover increased their distance from the resident male and decreased mating frequency during the three months prior to takeover. Females with infants under one-year-old had a marked effect on the specific time of takeover occurrence. These results suggested that female choice was the main factor deciding whether a takeover attempt was successful. Furthermore, rather than male conflict, females more often initiated and affected takeover and outcome, implying that the social status and competitive ability of the males played lesser roles during takeover.
基金This work has been supported by the National Natural Science Foundation of China under Grant No.61272519,the Specialized Research Fund for the Doctoral Program of Higher Education under Grant No.20120005110017,and the National Key Technology R&D Program under Grant No.2012BAH06B02
文摘Despite that existing data sharing systems in online social networks （OSNs） propose to encrypt data before sharing, the multiparty access control of encrypted data has become a challenging issue. In this paper, we propose a secure data sharing scheme in 0SNs based on ciphertext-policy attribute- based proxy re-encryption and secret sharing. In order to protect users＇ sensitive data, our scheme allows users to customize access policies of their data and then outsource encrypted data to the OSNs service provider. Our scheme presents a multiparty access control model, which enables the disseminator to update the access policy of ciphertext if their attributes satisfy the existing access policy. Further, we present a partial decryption construction in which the computation overhead of user is largely reduced by delegating most of the decryption operations to the OSNs service provider. We also provide checkability on the results returned from the OSNs service provider to guarantee the correctness of partial decrypted ciphertext. Moreover, our scheme presents an efficient attribute revocation method that achieves both forward and backward secrecy. The security and performance analysis results indicate that the proposed scheme is secure and efficient in OSNs.
