The existing data mining methods are mostly focused on relational databases and structured data, but not on complex structured data (like in extensible markup language(XML)). By converting XML document type descriptio...The existing data mining methods are mostly focused on relational databases and structured data, but not on complex structured data (like in extensible markup language(XML)). By converting XML document type description to the relational semantic recording XML data relations, and using an XML data mining language, the XML data mining system presents a strategy to mine information on XML.展开更多
In order to ensure the safety,quality and efficiency of computer numerical control(CNC)machine tool processing,a real-time monitoring and visible solution for CNC machine tools based on hyper text markup language(HTML...In order to ensure the safety,quality and efficiency of computer numerical control(CNC)machine tool processing,a real-time monitoring and visible solution for CNC machine tools based on hyper text markup language(HTML)5 is proposed.The characteristics of the real-time monitoring technology of CNC machine tools under the traditional Client/Server(C/S)structure are compared and analyzed,and the technical drawbacks are proposed.Web real-time communication technology and browser drawing technology are deeply studied.A real-time monitoring and visible system for CNC machine tool data is developed based on Metro platform,combining WebSocket real-time communication technology and Canvas drawing technology.The system architecture is given,and the functions and implementation methods of the system are described in detail.The practical application results show that the WebSocket real-time communication technology can effectively reduce the bandwidth and network delay and save server resources.The numerical control machine data monitoring system can intuitively reflect the machine data,and the visible effect is good.It realizes timely monitoring of equipment alarms and prompts maintenance and management personnel.展开更多
Based on China's industrial enterprises-customs matched data, this paper utilizes two-tier stochastic frontier analysis method to estimate and verify the extent to which selection effect and competition effect inf...Based on China's industrial enterprises-customs matched data, this paper utilizes two-tier stochastic frontier analysis method to estimate and verify the extent to which selection effect and competition effect influence exporting firms' markup. Our findings suggest that the interaction between selection effect and competition effect ultimately causes actual firm markup to be higher than the baseline markup by 7.11%. Exporting firms' actual markup is higher than the baseline markup by different degrees. In terms of the decomposition of selection effect, TFP explains for 28.05% of selection effect, and nonproductivity factors explain for the rest 71.95%. By controlling for the type of firms' export,the export-productivity paradox only exists for processing trade firms, which shows that with increasing trade facilitation, the policy incentives to encourage firms to export are major contributors to the low export markups.展开更多
In this paper,digital transformation is included in the heterogeneity model of firms.Based on a general equilibrium analysis,we find that under the effect of diminishing marginal productivity,digital transformation do...In this paper,digital transformation is included in the heterogeneity model of firms.Based on a general equilibrium analysis,we find that under the effect of diminishing marginal productivity,digital transformation does not always have a positive impact on firms'markups,but has an"inverted U-shaped"nonlinear influence,which first promotes and then inhibits markups.Firm innovation and firm productivity are the key micro-mechanisms for the above effects to play a role.Based on the analysis of typical facts and empirical data of listed companies,the measurement test yields the following results.First,digital transformation can significantly improve firms'markups when it is below a specific threshold value,but it will have a negative impact when it exceeds this value.That is,there is an"inverted U-shaped"nonlinear relationship between digital transformation and firms'markups.Second,the heterogeneity analysis shows that digital transformation has a greater effect on the markups of state-owned firms,export firms and technology-intensive firms than on the markups of other firms.Third,digital transformation has an impact on firms'markups through two key mechanisms:firm innovation ability and production eficiency.The quantitative empirical results confirm the correctness of the theoretical expectations.Therefore,firms need to grasp the strategic opportunities brought by the progress of digital technology and accelerate the process of promoting the digital transformation.Firms should make proper choices in the selection and arrangement of key areas,as well as avoid possible problems such as"too much".In this way,we can better consolidate the micro foundation of China's high-quality economic development.展开更多
文摘The existing data mining methods are mostly focused on relational databases and structured data, but not on complex structured data (like in extensible markup language(XML)). By converting XML document type description to the relational semantic recording XML data relations, and using an XML data mining language, the XML data mining system presents a strategy to mine information on XML.
文摘In order to ensure the safety,quality and efficiency of computer numerical control(CNC)machine tool processing,a real-time monitoring and visible solution for CNC machine tools based on hyper text markup language(HTML)5 is proposed.The characteristics of the real-time monitoring technology of CNC machine tools under the traditional Client/Server(C/S)structure are compared and analyzed,and the technical drawbacks are proposed.Web real-time communication technology and browser drawing technology are deeply studied.A real-time monitoring and visible system for CNC machine tool data is developed based on Metro platform,combining WebSocket real-time communication technology and Canvas drawing technology.The system architecture is given,and the functions and implementation methods of the system are described in detail.The practical application results show that the WebSocket real-time communication technology can effectively reduce the bandwidth and network delay and save server resources.The numerical control machine data monitoring system can intuitively reflect the machine data,and the visible effect is good.It realizes timely monitoring of equipment alarms and prompts maintenance and management personnel.
基金Sponsorship of the National Social Science Foundation (NSSF) Youth Project (16CJL014)the China Postdoctoral Science Special Foundation (2017T100001)
文摘Based on China's industrial enterprises-customs matched data, this paper utilizes two-tier stochastic frontier analysis method to estimate and verify the extent to which selection effect and competition effect influence exporting firms' markup. Our findings suggest that the interaction between selection effect and competition effect ultimately causes actual firm markup to be higher than the baseline markup by 7.11%. Exporting firms' actual markup is higher than the baseline markup by different degrees. In terms of the decomposition of selection effect, TFP explains for 28.05% of selection effect, and nonproductivity factors explain for the rest 71.95%. By controlling for the type of firms' export,the export-productivity paradox only exists for processing trade firms, which shows that with increasing trade facilitation, the policy incentives to encourage firms to export are major contributors to the low export markups.
文摘In this paper,digital transformation is included in the heterogeneity model of firms.Based on a general equilibrium analysis,we find that under the effect of diminishing marginal productivity,digital transformation does not always have a positive impact on firms'markups,but has an"inverted U-shaped"nonlinear influence,which first promotes and then inhibits markups.Firm innovation and firm productivity are the key micro-mechanisms for the above effects to play a role.Based on the analysis of typical facts and empirical data of listed companies,the measurement test yields the following results.First,digital transformation can significantly improve firms'markups when it is below a specific threshold value,but it will have a negative impact when it exceeds this value.That is,there is an"inverted U-shaped"nonlinear relationship between digital transformation and firms'markups.Second,the heterogeneity analysis shows that digital transformation has a greater effect on the markups of state-owned firms,export firms and technology-intensive firms than on the markups of other firms.Third,digital transformation has an impact on firms'markups through two key mechanisms:firm innovation ability and production eficiency.The quantitative empirical results confirm the correctness of the theoretical expectations.Therefore,firms need to grasp the strategic opportunities brought by the progress of digital technology and accelerate the process of promoting the digital transformation.Firms should make proper choices in the selection and arrangement of key areas,as well as avoid possible problems such as"too much".In this way,we can better consolidate the micro foundation of China's high-quality economic development.
