Purpose: Based on the weak tie theory, this paper proposes a series of connection indicators Acof weak tie subnets and weak tie nodes to detect research topics, recognize their connections, and understand their evolut...Purpose: Based on the weak tie theory, this paper proposes a series of connection indicators Acof weak tie subnets and weak tie nodes to detect research topics, recognize their connections, and understand their evolution.Design/methodology/approach: First, keywords are extracted from article titles and preprocessed. Second, high-frequency keywords are selected to generate weak tie co-occurrence networks. By removing the internal lines of clustered sub-topic networks, we focus on the analysis of weak tie subnets’ composition and functions and the weak tie nodes’ roles.Findings: The research topics’ clusters and themes changed yearly; the subnets clustered with technique-related and methodology-related topics have been the core, important subnets for years; while close subnets are highly independent, research topics are generally concentrated and most topics are application-related; the roles and functions of nodes and weak ties are diversified.Research limitations: The parameter values are somewhat inconsistent; the weak tie subnets and nodes are classified based on empirical observations, and the conclusions are not verified or compared to other methods.Practical implications: The research is valuable for detecting important research topics as well as their roles, interrelations, and evolution trends. Originality/value: To contribute to the strength of weak tie theory, the research translates weak and strong ties concepts to co-occurrence strength, and analyzes weak ties’ functions. Also, the research proposes a quantitative method to classify and measure the topics’ clusters and nodes.展开更多
We elaborate relevant theories of farmers' relational network,including the Differential Model of Association,the Strength of Weak Tie,Strength of Strong Tie and Favor and Face.The farmers' relational network ...We elaborate relevant theories of farmers' relational network,including the Differential Model of Association,the Strength of Weak Tie,Strength of Strong Tie and Favor and Face.The farmers' relational network in the Differential Model of Association can be divided into three layers:strong tie,weak tie and irrelative relationship according to Granovetter theory.These three layers have deep influence on opportunity selection during the undertaking,financing and enterprise development.With rational knowledge of these layers,farmers may exploit undertaking resources.On the basis of these,we made detailed analysis on farmers' selection of relations in the opportunity selection,financing and enterprise development stages.展开更多
为了适应微电网并网运行的需求,配电网正朝着主动控制与管理的方向发展。本文介绍了一种新型的柔性联络开关(Flexible tie switch, FTS),它可以代替传统的分段隔离开关或柔性联络开关,适用于配电网的主动潮流控制。FTS可以通过优化现有...为了适应微电网并网运行的需求,配电网正朝着主动控制与管理的方向发展。本文介绍了一种新型的柔性联络开关(Flexible tie switch, FTS),它可以代替传统的分段隔离开关或柔性联络开关,适用于配电网的主动潮流控制。FTS可以通过优化现有的网络容量,以便容纳更多的分布式发电单元。为了分析其有效性,首先根据FTS在dq坐标系中的简化数学模型,采用典型的双闭环控制算法,在PSCAD中研究了FTS的动态功率控制性能,并将最小网络损失和电压曲线优化被设定为潮流控制的目标。考虑到电压偏差约束、FTS的容量限制以及功率损耗,建立了以FTS为控制变量的多目标优化函数。当负荷的功率约束较为复杂的情况下,利用粒子群算法来寻找最佳解决方案。结果表明,当FTS被用于配电网的潮流控制时,系统网损明显降低,电压曲线也得到了优化。展开更多
基金funded by the National Social Science Youth Project “Study on the Interdisciplinary Subject Identification and Prediction” (Grant No.:14CTQ033)
文摘Purpose: Based on the weak tie theory, this paper proposes a series of connection indicators Acof weak tie subnets and weak tie nodes to detect research topics, recognize their connections, and understand their evolution.Design/methodology/approach: First, keywords are extracted from article titles and preprocessed. Second, high-frequency keywords are selected to generate weak tie co-occurrence networks. By removing the internal lines of clustered sub-topic networks, we focus on the analysis of weak tie subnets’ composition and functions and the weak tie nodes’ roles.Findings: The research topics’ clusters and themes changed yearly; the subnets clustered with technique-related and methodology-related topics have been the core, important subnets for years; while close subnets are highly independent, research topics are generally concentrated and most topics are application-related; the roles and functions of nodes and weak ties are diversified.Research limitations: The parameter values are somewhat inconsistent; the weak tie subnets and nodes are classified based on empirical observations, and the conclusions are not verified or compared to other methods.Practical implications: The research is valuable for detecting important research topics as well as their roles, interrelations, and evolution trends. Originality/value: To contribute to the strength of weak tie theory, the research translates weak and strong ties concepts to co-occurrence strength, and analyzes weak ties’ functions. Also, the research proposes a quantitative method to classify and measure the topics’ clusters and nodes.
基金Supported by the Project of Rural Development Research Center of Anhui University (2011sk690)Innovative Experimental Program for Undergraduates of Anhui University (xj103575100)
文摘We elaborate relevant theories of farmers' relational network,including the Differential Model of Association,the Strength of Weak Tie,Strength of Strong Tie and Favor and Face.The farmers' relational network in the Differential Model of Association can be divided into three layers:strong tie,weak tie and irrelative relationship according to Granovetter theory.These three layers have deep influence on opportunity selection during the undertaking,financing and enterprise development.With rational knowledge of these layers,farmers may exploit undertaking resources.On the basis of these,we made detailed analysis on farmers' selection of relations in the opportunity selection,financing and enterprise development stages.
文摘为了适应微电网并网运行的需求,配电网正朝着主动控制与管理的方向发展。本文介绍了一种新型的柔性联络开关(Flexible tie switch, FTS),它可以代替传统的分段隔离开关或柔性联络开关,适用于配电网的主动潮流控制。FTS可以通过优化现有的网络容量,以便容纳更多的分布式发电单元。为了分析其有效性,首先根据FTS在dq坐标系中的简化数学模型,采用典型的双闭环控制算法,在PSCAD中研究了FTS的动态功率控制性能,并将最小网络损失和电压曲线优化被设定为潮流控制的目标。考虑到电压偏差约束、FTS的容量限制以及功率损耗,建立了以FTS为控制变量的多目标优化函数。当负荷的功率约束较为复杂的情况下,利用粒子群算法来寻找最佳解决方案。结果表明,当FTS被用于配电网的潮流控制时,系统网损明显降低,电压曲线也得到了优化。
