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Electronic Commerce Research - We consider a platform providing free content for users and earning profit from the sale of advertising. The platform can collect and analyze personal data to... 相似文献
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为缓解我国水、能源和粮食资源紧张问题,促进资源可持续利用,构建水-能源-粮食系统,利用耦合协调度模型对我国的30个省(自治区、直辖市)进行测算,并利用空间杜宾模型分析主要影响因素。结果表明:2003—2017年,我国能源、粮食评价[JP]指数高于水资源评价指数,系统综合评价指数逐年递增;大部分省份耦合协调度处于初级协调水平且呈现逐年上升的态势,个别省份耦合协调度濒临失调;耦合协调度空间自相关性较强,虽有明显波动,但是呈现逐年加强的态势;影响耦合协调度的主要因素有从业人口数、固定资产投资额、人均生产总值、人口总数、[JP]文盲人口占比、工业污染排放、城镇化。 相似文献
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This editorial paper provides an overview of new advances on hardware security challenges and promising solutions for real world applications. It first presents the increasing hardware vulnerabilities with the emergence of diverse computing platforms. Then, it details the technical challenges, research opportunities, and potential solutions to cyber-attacks on -physical- devices. 相似文献
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Forecasting the volatility and correlation among different kinds of assets has important applications in areas such as risk management, options pricing, and asset allocation. This paper mainly uses a novel multivariate Generalized Autoregressive Score (GAS) model to analyze and forecast volatilities and correlations between Brent, WTI and gold prices. The time-varying parameters of multivariate GAS model for a given distribution of crude oil and gold prices is observed which is supported by Doornik-Hansen test. The testing results of time-varying parameters based on LRT statistics reveal that the dependent structure between Brent and gold prices is more complex than those of WTI and gold. The estimation results show that the multivariate GAS method well captures the volatility persistence and nonlinear interaction effects between the crude oil and gold markets. In addition, we compare the forecasting performance of the GAS with the classical Dynamic Conditional Correlation Generalized Auto-Regressive Conditional Heteroskedasticity (DCC-GARCH) model, and find that the forecasting power of volatility and correlation in multivariate GAS model is better than the DCC-GARCH model. 相似文献
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Environmental problems brought by industry are attracting extensive attention so a comprehensive analysis of industrial environmental performance is increasingly important. However, the comparison of industrial sector efficiencies is complicated by the fact that the natural resources consumed and/or the pollutants discharged by each sector may differ. In this paper, we extend the DEA model to consider two-sided non-homogeneous problems, handling DMU sets that have non-homogeneity in both inputs and outputs. This is different from the previous researches which generally focus on regional data to avoid non-homogeneity. Today environmental reform and energy conservation in various industrial sectors are both parts of the basic state policy of China. The empirical results show that: (1) Sectors' efficiencies are still low and unbalanced. The Recycling and Disposal of Waste department achieves the best energy saving and emission reduction efficiency. (2) 38 sectors can be clustered into four groups and set new benchmark in each group. (3) The overall efficiency of 38 industrial sectors in China maintained a rising trend in five years. With this more realistic analysis of environmental efficiency, the Chinese government can make more informed decisions to realize sustainable industrial development. 相似文献
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