The CIIE demonstrates China’s commitment to opening up and cooperation The eighth China International Import Expo(CIIE),held in Shanghai from 5 to 10 November,once again underscored China’s commitment to deepening i...The CIIE demonstrates China’s commitment to opening up and cooperation The eighth China International Import Expo(CIIE),held in Shanghai from 5 to 10 November,once again underscored China’s commitment to deepening institutional opening up.展开更多
The research explores the long-term connection between Greece’s agricultural output,with a focus on both crop and livestock production,and crucial environmental factors like water usage and energy consumption.Through...The research explores the long-term connection between Greece’s agricultural output,with a focus on both crop and livestock production,and crucial environmental factors like water usage and energy consumption.Through linear regression analysis,the study investigates how these factors affect agricultural value-added,providing insights into the sustainability and efficiency of Greece’s farming sector.The results show a significant(p<0.05)positive relationship between crop production and agricultural value-added,as well as the significant influence of water usage and energy consumption on the productivity of both crops and livestock.For livestock farming,the analysis revealed a weaker contribution to agricultural value-added at the national level,likely due to structural inefficiencies in the sector.While livestock production benefits significantly from water and energy inputs,it does not have as substantial an economic impact compared to crop production.This research contributes to the field of agricultural economics by offering a historical perspective on how resource management influences agricultural performance over time.It highlights the significance of sustainable practices,especially in areas like the periphery of Western Macedonia,which are shifting from conventional energy sources like lignite to renewable energy.The findings advocate for policies that promote water conservation,energy efficiency,and smart agriculture to enhance productivity and support regional development.展开更多
In the rapidly evolving landscape of natural language processing(NLP)and sentiment analysis,improving the accuracy and efficiency of sentiment classification models is crucial.This paper investigates the performance o...In the rapidly evolving landscape of natural language processing(NLP)and sentiment analysis,improving the accuracy and efficiency of sentiment classification models is crucial.This paper investigates the performance of two advanced models,the Large Language Model(LLM)LLaMA model and NLP BERT model,in the context of airline review sentiment analysis.Through fine-tuning,domain adaptation,and the application of few-shot learning,the study addresses the subtleties of sentiment expressions in airline-related text data.Employing predictive modeling and comparative analysis,the research evaluates the effectiveness of Large Language Model Meta AI(LLaMA)and Bidirectional Encoder Representations from Transformers(BERT)in capturing sentiment intricacies.Fine-tuning,including domain adaptation,enhances the models'performance in sentiment classification tasks.Additionally,the study explores the potential of few-shot learning to improve model generalization using minimal annotated data for targeted sentiment analysis.By conducting experiments on a diverse airline review dataset,the research quantifies the impact of fine-tuning,domain adaptation,and few-shot learning on model performance,providing valuable insights for industries aiming to predict recommendations and enhance customer satisfaction through a deeper understanding of sentiment in user-generated content(UGC).This research contributes to refining sentiment analysis models,ultimately fostering improved customer satisfaction in the airline industry.展开更多
This study assessed the connectedness between oil shocks and industry stock indexes in the United States(US).We consider the normal and extreme conditions across different frequency horizons,and the quantile time–fre...This study assessed the connectedness between oil shocks and industry stock indexes in the United States(US).We consider the normal and extreme conditions across different frequency horizons,and the quantile time–frequency connectedness method is used to determine the tail risk contagion under different frequency horizons.Our results reveal that the short-term frequency connectedness significantly exceeds the long-term frequency connectedness.We also indicate that the connectedness in the lower and upper quantiles is greater than at the conditional mean.Importantly,oil risk shock is the biggest net transmitter of shocks to the US sectors in normal and extreme conditions,highlighting that oil risk shocks cause substantial variations in US sector stock returns in the short,medium,and long term.Finally,QAR(3)model demonstrates the significant impact of oil risk shocks on US sector stock returns during extreme and normal conditions.Therefore,our study underscores the role of asymmetry in the reaction of US sector stock returns to oil-related shocks,and we suggest that policies aimed at overcoming the adverse effects of oil shocks on stock markets and promoting financial stability should incorporate asymmetric features.展开更多
Supply chain partnerships are an essential component of business innovations.This study uses data on A-share listed companies on the Shanghai and Shenzhen stock exchanges from 2012 to 2022 to conduct a multi-period di...Supply chain partnerships are an essential component of business innovations.This study uses data on A-share listed companies on the Shanghai and Shenzhen stock exchanges from 2012 to 2022 to conduct a multi-period difference-in-differences analysis based on a list of green supply chain management(GSM)companies.We find that GSM significantly promotes low-carbon technology innovations(LCT)of upstream enterprises.The mechanism analysis indicates that GSM has a resource effect and signal effect that generate LCT spillovers.In terms of the resource effect,GSM companies offer green credit and support green procurement,thereby providing financial support for green investments in upstream LCT.In terms of a signaling effect,GSM strengthens the effectiveness of institutional investors,the public,and online media in supervising upstream suppliers’green credentials,thereby promoting upstream LCT.A heterogeneity analysis shows that when midstream companies are state-owned enterprises or industry leaders,and when the concentration and stability of supply chain purchase relationships are higher,the LCT spillover effects of GSM are more pronounced.Further analysis reveals that GSM has bidirectional horizontal spillover effects and that upstream unidirectional vertical spillover effects are limited to first-level suppliers.Additionally,under the premise of not compromising economic benefits and stability,GSM shows an emerging trend of transitioning from environmentally compliant“light green”supply chains to“deep green”supply chains focused on pollution reduction,carbon reduction,and energy conservation.展开更多
Using data from the 2022 China Family Panel Studies(CFPS),this study selects 11,375 dual-spouse households as the research sample and constructs a comprehensive housework division index via the entropy weight method.T...Using data from the 2022 China Family Panel Studies(CFPS),this study selects 11,375 dual-spouse households as the research sample and constructs a comprehensive housework division index via the entropy weight method.The index integrates four dimensions:participation subject,time allocation,content type,and fairness perception,aiming to explore the fairness level of housework division and group differences in Chinese households.The results show that the overall fairness of housework division in Chinese households is relatively low:the mean value of the index(after 10,000-fold linear expansion)is 0.0632,showing a significant right-skewed distribution,with most households concentrated in the"low-fairness"range and only a few achieving relatively balanced division.Significant group differences exist:rural households have a slightly higher housework division index(0.0659)than urban households(0.0608);male respondents have a higher index(0.0660)than female respondents(0.0603);and the high-education group has a significantly lower index(0.0501)than the low-education group(0.0653).The fairness of housework division is jointly influenced by structural factors and perceptual factors,with an obvious"concept-action gap":74.02%of respondents perceive housework division as"fair",but the low index level indicates this perception mostly stems from normative adaptation rather than objective balance.This study provides empirical evidence for optimizing family labor allocation and promoting gender equality.展开更多
This study explores the impact of intergenerational differences on farmers' terrace abandonment in response to increasing intergenerational differentiation among rural households and the practical issue of terrace...This study explores the impact of intergenerational differences on farmers' terrace abandonment in response to increasing intergenerational differentiation among rural households and the practical issue of terrace abandonment. Logit and Tobit models are employed to conduct empirical analysis and it is found that terrace abandonment increases sequentially among the new, middle, and old generations, confirming that intergenerational differences significantly influence whether farmers abandon terraces and the terrace abandonment scale. Village characteristics and government subsidies significantly influence farmers' terrace abandonment. An increase in the number of migrant workers in the village increases terrace abandonment among new and middle generation farmers, whereas an increase in the distance from the village to the county significantly increases terrace abandonment among old generation farmers. An increase in the village's total population significantly reduces terrace abandonment among new generation farmers. An increase in government subsidies significantly reduces terrace abandonment among middle and old generation farmers. The impact of intergenerational differences on terrace abandonment is more pronounced in low-altitude areas. To reduce terrace abandonment, it is necessary to promote terrace transfer, develop characteristic agriculture, improve terrace farming subsidies, and propose targeted strategies for the different generations of farmers.展开更多
Digital transformation,as a recent trend in socioeconomic development,is considered as a critical pathway for urban carbon reduction because of its potential to increase productivity and energy efficiency.However,few ...Digital transformation,as a recent trend in socioeconomic development,is considered as a critical pathway for urban carbon reduction because of its potential to increase productivity and energy efficiency.However,few studies have explored the relationship between urban digitalization and carbon emissions(CE).Therefore,this study systematically analyzed the spatiotemporal distribution and interaction mechanism between digitalization and CE in the Yangtze River Delta(YRD)urban agglomerations of China during 2006-2020 based on a multidimensional indicator system,including digitalization industry level,digitalization application level,and urban green digitalization willingness.The findings revealed that both digitalization and CE in the YRD exhibit a significant and synchronously evolving“core-periphery”spatial pattern.Core cities generated substantial positive spillover effect on periphery cities through technology diffusion and policy demonstration,advancing both regional digitalization and the collaborative governance of CE.However,digitalization had dual impact on CE.On the one hand,it promoted the reduction of CE by enhancing energy efficiency,optimizing industrial structures,and promoting the application of green technologies.On the other hand,the expansion of digital infrastructure introduced a potential risk of increased energy consumption.Therefore,targeted policy recommendations are proposed to facilitate the coordination of environmental sustainability and digitalization in the YRD.This study provides empirical support and policy insights for advancing the coordinated development of regional digital transformation and green low-carbon initiatives.展开更多
This study examines a comprehensive set of 30 cross-sectional anomalies in the Chinese A-share market to investigate whether incorporating investor sentiment as conditioning information enhances the explanatory power ...This study examines a comprehensive set of 30 cross-sectional anomalies in the Chinese A-share market to investigate whether incorporating investor sentiment as conditioning information enhances the explanatory power of asset pricing models.Utilizing a long–short portfolio strategy and Fama–MacBeth cross-sectional regression,we find that trading-based anomalies outnumber accounting-based anomalies in the Chinese market.Our results demonstrate that conditional models significantly outperform their unconditional counterparts.Notably,investor sentiment is crucial for capturing the size anomaly when excluding observations from the COVID-19 pandemic period.Additionally,it substantially improves the ability of conditional Fama–French three-factor models to capture individual anomalies and enhances the return–prediction accuracy of conditional CAPMs.We suggest further investigating high-frequency investor sentiment-based conditional models to anticipate stock price fluctuations during extraordinary public health events.展开更多
Metro systems are important transport infrastructures in megacities,and their long-term operational safety is challenged by frequent external disturbances,such as environmental extremes and human construction activ-it...Metro systems are important transport infrastructures in megacities,and their long-term operational safety is challenged by frequent external disturbances,such as environmental extremes and human construction activ-ities.A metro system must be resilient to resist,adapt to,and recover its performance when such disruptions occur.Current studies on metro system resilience often lack a comprehensive view from a complex system perspective,leading to a plethora of choices for methods of analysis and indicators applied to different metro systems and external disturbances.Therefore,the present paper aims to provide a comprehensive review of the topics and works revolving around the resilience of metro systems.It first clarifies the concept of metro system resilience based on classical definitions from a technical perspective.Metro resilience encompasses both the structural and operational aspects of metro systems,including their damage mechanisms,analysis methods and indicators of resilience.Methods for enhancing metro system resilience across structural,operational and monitoring dimensions are explored.Finally,future research directions are discussed,emphasizing the impor-tance of considering the"system of systems"formed by interdependent infrastructure,refining uncertainty analysis,and investigating the opportunities arising from the application of artificial intelligence for improving metro system resilience against external disturbances.展开更多
Chinese farmers are often accused of overusing pesticides that play a crucial role in enhancing crop yield by reducing losses to crop pests. Pesticide overuse has caused a series of negative health and environmental e...Chinese farmers are often accused of overusing pesticides that play a crucial role in enhancing crop yield by reducing losses to crop pests. Pesticide overuse has caused a series of negative health and environmental externalities. This paper quantiifes the productivity effect and the optimal amount of pesticides in rice, cotton and maize production in China from the economic perspective. Using survey data col ected in 2012 and 2013, both Cobb-Douglas and Weibul damage control speciifcations are used to estimate the production function. Results show that pesticides have statistical y signiifcant pro-ductivity effect on crop yield. On the condition of Weibul damage control speciifcations, the marginal products of 1 kg of the active ingredients of pesticides for rice, cotton and maize are 71.06, 22.73 and 98.45 kg, respectively. However, 57, 64 and 17%of the actual amount of pesticides are overused for rice, cotton and maize, respectively. Moreover, the productivity effect of pesticides would be overestimated using Cobb-Douglas speciifcation without incorporating a damage control agent.展开更多
The reduction of GHG emissions to reverse the greenhouse effect is one of the main challenges in this century.In this paper we pursue two objectives.First,we analyze the evolution of GHG emissions in Spain in 2008–20...The reduction of GHG emissions to reverse the greenhouse effect is one of the main challenges in this century.In this paper we pursue two objectives.First,we analyze the evolution of GHG emissions in Spain in 2008–2018,at both the global and sectoral levels,with the variation in emissions decomposed into a set of determining factors.Second,we propose several actions specifically oriented to more tightly controlling the level of emissions.Our results showed a remarkable reduction(18.44%)in GHG emissions,mainly due to the intensity effect,but also to the production-per-capita effect.We detected somewhat different patterns among the various sectors analyzed.While the intensity effect was the most influential one in the agricultural,transport,and others sectors,the production-per-capita effect was predominant in the case of industry.The carbonization effect was revealed as crucial in the commerce sector.The above findings highlight the importance of the energy efficiency measures taken in recent years in the Spanish economy,also pointing to the need to deepen those strategies and to propose new measures that entail greater efficiency in emissions.Additional efforts in areas like innovation,R&D,diffusion of more eco-friendly technologies,and a greater use of greener energies all prove to be essential reduction actions to fight the greenhouse effect.展开更多
This study examines the development and trends of China’s alfalfa market and imports, identifies key factors for the rapid increase in China’s alfalfa imports, and discusses potential impacts of the U.S.-China trade...This study examines the development and trends of China’s alfalfa market and imports, identifies key factors for the rapid increase in China’s alfalfa imports, and discusses potential impacts of the U.S.-China trade dispute and retaliations on the alfalfa markets and trade in both nations. China’s rapid transition toward larger-scale commercial dairy production, with enhanced feed and cost management as well as quality and safety control, and its limited resources for high-quality alfalfa production are key factors for the dramatic increase in its alfalfa imports, from 19 601 metric tons in 2008 to 1.38 million metric tons(mmt) in 2018. While the United States dominated China’s alfalfa imports with an average share of 97.01% from 2007 to 2017, the share dropped to 83.76% in 2018 and 63.28% in January 2019 due to the trade dispute and retaliations started in 2018. China will likely remain a large importer of alfalfa because of both its growing demand and the comparative advantages of imported alfalfa in quality and price, but the imports from the United States will be highly affected by the ongoing trade dispute and negotiations. China is also expected to make more efforts to reduce its dependence on U.S. alfalfa through increased investment in domestic alfalfa production and identification of alternative sources of alfalfa and other hay imports.展开更多
The objective of this work is to provide decision-making processes with an updated/real picture of the mobile resources in industrial environments through a constant feedback of information.The combination of identifi...The objective of this work is to provide decision-making processes with an updated/real picture of the mobile resources in industrial environments through a constant feedback of information.The combination of identification technologies and wireless sensor networks(WSN) is proposed as a key development to guarantee an accurate and timely supply of online information regarding the localization and tracking of the mobile wireless devices.This approach uses a cooperative and distributed localization system,called ZigID,which is a WSN based on a Zigbee network with radio frequency identification(RFID) active tags as end nodes.The WSN can recover not only the ID information stored at the tags attached to mobile resources,but also any other useful data captured by specific sensors for acceleration,temperature,humidity and fuel status.This paper also shows the development of ZigID,including devices and information flows,as well as its implementation in ground handling operations at the Ciudad Real Central Airport,Spain.展开更多
For studying new and renewable energy as a substitute for fossil energy in primary energy consumption and its impact on carbon emissions to cope with economic uncertainties, a multi-sector DSGE model was employed to s...For studying new and renewable energy as a substitute for fossil energy in primary energy consumption and its impact on carbon emissions to cope with economic uncertainties, a multi-sector DSGE model was employed to simulate the dynamic impact on carbon emissions and macroeconomic development. The structural adjustment of energy consumption and the carbon emissions mitigation policy were considered in the model. The simulation results showed that using new and renewable energy instead of fossil energy is an optimal choice for the firms to comply with the regulations of carbon emission mitigation policy. Structural adjustment of energy consumption is the best route to achieve the dual goal of economic development and carbon emission reduction. Unexpected sharp fall in free carbon quota has a negative impact on the economy.展开更多
文摘The CIIE demonstrates China’s commitment to opening up and cooperation The eighth China International Import Expo(CIIE),held in Shanghai from 5 to 10 November,once again underscored China’s commitment to deepening institutional opening up.
文摘The research explores the long-term connection between Greece’s agricultural output,with a focus on both crop and livestock production,and crucial environmental factors like water usage and energy consumption.Through linear regression analysis,the study investigates how these factors affect agricultural value-added,providing insights into the sustainability and efficiency of Greece’s farming sector.The results show a significant(p<0.05)positive relationship between crop production and agricultural value-added,as well as the significant influence of water usage and energy consumption on the productivity of both crops and livestock.For livestock farming,the analysis revealed a weaker contribution to agricultural value-added at the national level,likely due to structural inefficiencies in the sector.While livestock production benefits significantly from water and energy inputs,it does not have as substantial an economic impact compared to crop production.This research contributes to the field of agricultural economics by offering a historical perspective on how resource management influences agricultural performance over time.It highlights the significance of sustainable practices,especially in areas like the periphery of Western Macedonia,which are shifting from conventional energy sources like lignite to renewable energy.The findings advocate for policies that promote water conservation,energy efficiency,and smart agriculture to enhance productivity and support regional development.
文摘In the rapidly evolving landscape of natural language processing(NLP)and sentiment analysis,improving the accuracy and efficiency of sentiment classification models is crucial.This paper investigates the performance of two advanced models,the Large Language Model(LLM)LLaMA model and NLP BERT model,in the context of airline review sentiment analysis.Through fine-tuning,domain adaptation,and the application of few-shot learning,the study addresses the subtleties of sentiment expressions in airline-related text data.Employing predictive modeling and comparative analysis,the research evaluates the effectiveness of Large Language Model Meta AI(LLaMA)and Bidirectional Encoder Representations from Transformers(BERT)in capturing sentiment intricacies.Fine-tuning,including domain adaptation,enhances the models'performance in sentiment classification tasks.Additionally,the study explores the potential of few-shot learning to improve model generalization using minimal annotated data for targeted sentiment analysis.By conducting experiments on a diverse airline review dataset,the research quantifies the impact of fine-tuning,domain adaptation,and few-shot learning on model performance,providing valuable insights for industries aiming to predict recommendations and enhance customer satisfaction through a deeper understanding of sentiment in user-generated content(UGC).This research contributes to refining sentiment analysis models,ultimately fostering improved customer satisfaction in the airline industry.
基金supported by the Ministry of Education of the Republic of Korea and the National Research Foundation of Korea(NRF-2024S1A5A2A01028034).
文摘This study assessed the connectedness between oil shocks and industry stock indexes in the United States(US).We consider the normal and extreme conditions across different frequency horizons,and the quantile time–frequency connectedness method is used to determine the tail risk contagion under different frequency horizons.Our results reveal that the short-term frequency connectedness significantly exceeds the long-term frequency connectedness.We also indicate that the connectedness in the lower and upper quantiles is greater than at the conditional mean.Importantly,oil risk shock is the biggest net transmitter of shocks to the US sectors in normal and extreme conditions,highlighting that oil risk shocks cause substantial variations in US sector stock returns in the short,medium,and long term.Finally,QAR(3)model demonstrates the significant impact of oil risk shocks on US sector stock returns during extreme and normal conditions.Therefore,our study underscores the role of asymmetry in the reaction of US sector stock returns to oil-related shocks,and we suggest that policies aimed at overcoming the adverse effects of oil shocks on stock markets and promoting financial stability should incorporate asymmetric features.
文摘Supply chain partnerships are an essential component of business innovations.This study uses data on A-share listed companies on the Shanghai and Shenzhen stock exchanges from 2012 to 2022 to conduct a multi-period difference-in-differences analysis based on a list of green supply chain management(GSM)companies.We find that GSM significantly promotes low-carbon technology innovations(LCT)of upstream enterprises.The mechanism analysis indicates that GSM has a resource effect and signal effect that generate LCT spillovers.In terms of the resource effect,GSM companies offer green credit and support green procurement,thereby providing financial support for green investments in upstream LCT.In terms of a signaling effect,GSM strengthens the effectiveness of institutional investors,the public,and online media in supervising upstream suppliers’green credentials,thereby promoting upstream LCT.A heterogeneity analysis shows that when midstream companies are state-owned enterprises or industry leaders,and when the concentration and stability of supply chain purchase relationships are higher,the LCT spillover effects of GSM are more pronounced.Further analysis reveals that GSM has bidirectional horizontal spillover effects and that upstream unidirectional vertical spillover effects are limited to first-level suppliers.Additionally,under the premise of not compromising economic benefits and stability,GSM shows an emerging trend of transitioning from environmentally compliant“light green”supply chains to“deep green”supply chains focused on pollution reduction,carbon reduction,and energy conservation.
文摘Using data from the 2022 China Family Panel Studies(CFPS),this study selects 11,375 dual-spouse households as the research sample and constructs a comprehensive housework division index via the entropy weight method.The index integrates four dimensions:participation subject,time allocation,content type,and fairness perception,aiming to explore the fairness level of housework division and group differences in Chinese households.The results show that the overall fairness of housework division in Chinese households is relatively low:the mean value of the index(after 10,000-fold linear expansion)is 0.0632,showing a significant right-skewed distribution,with most households concentrated in the"low-fairness"range and only a few achieving relatively balanced division.Significant group differences exist:rural households have a slightly higher housework division index(0.0659)than urban households(0.0608);male respondents have a higher index(0.0660)than female respondents(0.0603);and the high-education group has a significantly lower index(0.0501)than the low-education group(0.0653).The fairness of housework division is jointly influenced by structural factors and perceptual factors,with an obvious"concept-action gap":74.02%of respondents perceive housework division as"fair",but the low index level indicates this perception mostly stems from normative adaptation rather than objective balance.This study provides empirical evidence for optimizing family labor allocation and promoting gender equality.
基金Key Program of National Natural Science Foundation of China,No.41930757National Natural Science Foundation of China,No.42371285。
文摘This study explores the impact of intergenerational differences on farmers' terrace abandonment in response to increasing intergenerational differentiation among rural households and the practical issue of terrace abandonment. Logit and Tobit models are employed to conduct empirical analysis and it is found that terrace abandonment increases sequentially among the new, middle, and old generations, confirming that intergenerational differences significantly influence whether farmers abandon terraces and the terrace abandonment scale. Village characteristics and government subsidies significantly influence farmers' terrace abandonment. An increase in the number of migrant workers in the village increases terrace abandonment among new and middle generation farmers, whereas an increase in the distance from the village to the county significantly increases terrace abandonment among old generation farmers. An increase in the village's total population significantly reduces terrace abandonment among new generation farmers. An increase in government subsidies significantly reduces terrace abandonment among middle and old generation farmers. The impact of intergenerational differences on terrace abandonment is more pronounced in low-altitude areas. To reduce terrace abandonment, it is necessary to promote terrace transfer, develop characteristic agriculture, improve terrace farming subsidies, and propose targeted strategies for the different generations of farmers.
文摘Digital transformation,as a recent trend in socioeconomic development,is considered as a critical pathway for urban carbon reduction because of its potential to increase productivity and energy efficiency.However,few studies have explored the relationship between urban digitalization and carbon emissions(CE).Therefore,this study systematically analyzed the spatiotemporal distribution and interaction mechanism between digitalization and CE in the Yangtze River Delta(YRD)urban agglomerations of China during 2006-2020 based on a multidimensional indicator system,including digitalization industry level,digitalization application level,and urban green digitalization willingness.The findings revealed that both digitalization and CE in the YRD exhibit a significant and synchronously evolving“core-periphery”spatial pattern.Core cities generated substantial positive spillover effect on periphery cities through technology diffusion and policy demonstration,advancing both regional digitalization and the collaborative governance of CE.However,digitalization had dual impact on CE.On the one hand,it promoted the reduction of CE by enhancing energy efficiency,optimizing industrial structures,and promoting the application of green technologies.On the other hand,the expansion of digital infrastructure introduced a potential risk of increased energy consumption.Therefore,targeted policy recommendations are proposed to facilitate the coordination of environmental sustainability and digitalization in the YRD.This study provides empirical support and policy insights for advancing the coordinated development of regional digital transformation and green low-carbon initiatives.
基金financially supported by:National Natural Science Foundation of China(72261002,72141304)Youth Foundation for Humanities and Social Sciences Research of the Ministry of Education(22YJC790190)+1 种基金National Key Research and Development Program of China(2022YFC3303304)Student Research Program of Guizhou University of Finance and Economics(2022ZXS).
文摘This study examines a comprehensive set of 30 cross-sectional anomalies in the Chinese A-share market to investigate whether incorporating investor sentiment as conditioning information enhances the explanatory power of asset pricing models.Utilizing a long–short portfolio strategy and Fama–MacBeth cross-sectional regression,we find that trading-based anomalies outnumber accounting-based anomalies in the Chinese market.Our results demonstrate that conditional models significantly outperform their unconditional counterparts.Notably,investor sentiment is crucial for capturing the size anomaly when excluding observations from the COVID-19 pandemic period.Additionally,it substantially improves the ability of conditional Fama–French three-factor models to capture individual anomalies and enhances the return–prediction accuracy of conditional CAPMs.We suggest further investigating high-frequency investor sentiment-based conditional models to anticipate stock price fluctuations during extraordinary public health events.
基金supported by National Key R&D Program of China 2024YFC3808804National Natural Science Foundation of China NO.52478411+1 种基金China Scholarship Council No.202506260003Jinan Rail Transit Group Co.,Ltd(ggjn-sd-gd2022008fw).
文摘Metro systems are important transport infrastructures in megacities,and their long-term operational safety is challenged by frequent external disturbances,such as environmental extremes and human construction activ-ities.A metro system must be resilient to resist,adapt to,and recover its performance when such disruptions occur.Current studies on metro system resilience often lack a comprehensive view from a complex system perspective,leading to a plethora of choices for methods of analysis and indicators applied to different metro systems and external disturbances.Therefore,the present paper aims to provide a comprehensive review of the topics and works revolving around the resilience of metro systems.It first clarifies the concept of metro system resilience based on classical definitions from a technical perspective.Metro resilience encompasses both the structural and operational aspects of metro systems,including their damage mechanisms,analysis methods and indicators of resilience.Methods for enhancing metro system resilience across structural,operational and monitoring dimensions are explored.Finally,future research directions are discussed,emphasizing the impor-tance of considering the"system of systems"formed by interdependent infrastructure,refining uncertainty analysis,and investigating the opportunities arising from the application of artificial intelligence for improving metro system resilience against external disturbances.
基金financial support from the National Natural Science Foundation of China (71173014 and 71210004)the China Scholarship Council (201306030053)
文摘Chinese farmers are often accused of overusing pesticides that play a crucial role in enhancing crop yield by reducing losses to crop pests. Pesticide overuse has caused a series of negative health and environmental externalities. This paper quantiifes the productivity effect and the optimal amount of pesticides in rice, cotton and maize production in China from the economic perspective. Using survey data col ected in 2012 and 2013, both Cobb-Douglas and Weibul damage control speciifcations are used to estimate the production function. Results show that pesticides have statistical y signiifcant pro-ductivity effect on crop yield. On the condition of Weibul damage control speciifcations, the marginal products of 1 kg of the active ingredients of pesticides for rice, cotton and maize are 71.06, 22.73 and 98.45 kg, respectively. However, 57, 64 and 17%of the actual amount of pesticides are overused for rice, cotton and maize, respectively. Moreover, the productivity effect of pesticides would be overestimated using Cobb-Douglas speciifcation without incorporating a damage control agent.
基金funding from the Spanish Ministry of Science and Innovation,project MCI-21PID2020-115183RB-C21。
文摘The reduction of GHG emissions to reverse the greenhouse effect is one of the main challenges in this century.In this paper we pursue two objectives.First,we analyze the evolution of GHG emissions in Spain in 2008–2018,at both the global and sectoral levels,with the variation in emissions decomposed into a set of determining factors.Second,we propose several actions specifically oriented to more tightly controlling the level of emissions.Our results showed a remarkable reduction(18.44%)in GHG emissions,mainly due to the intensity effect,but also to the production-per-capita effect.We detected somewhat different patterns among the various sectors analyzed.While the intensity effect was the most influential one in the agricultural,transport,and others sectors,the production-per-capita effect was predominant in the case of industry.The carbonization effect was revealed as crucial in the commerce sector.The above findings highlight the importance of the energy efficiency measures taken in recent years in the Spanish economy,also pointing to the need to deepen those strategies and to propose new measures that entail greater efficiency in emissions.Additional efforts in areas like innovation,R&D,diffusion of more eco-friendly technologies,and a greater use of greener energies all prove to be essential reduction actions to fight the greenhouse effect.
基金the Vermont Agricultural Experiment Station at the University Vermont,USA,and the National Social Science Fund of China(17ZDA067)for financial support of this project。
文摘This study examines the development and trends of China’s alfalfa market and imports, identifies key factors for the rapid increase in China’s alfalfa imports, and discusses potential impacts of the U.S.-China trade dispute and retaliations on the alfalfa markets and trade in both nations. China’s rapid transition toward larger-scale commercial dairy production, with enhanced feed and cost management as well as quality and safety control, and its limited resources for high-quality alfalfa production are key factors for the dramatic increase in its alfalfa imports, from 19 601 metric tons in 2008 to 1.38 million metric tons(mmt) in 2018. While the United States dominated China’s alfalfa imports with an average share of 97.01% from 2007 to 2017, the share dropped to 83.76% in 2018 and 63.28% in January 2019 due to the trade dispute and retaliations started in 2018. China will likely remain a large importer of alfalfa because of both its growing demand and the comparative advantages of imported alfalfa in quality and price, but the imports from the United States will be highly affected by the ongoing trade dispute and negotiations. China is also expected to make more efforts to reduce its dependence on U.S. alfalfa through increased investment in domestic alfalfa production and identification of alternative sources of alfalfa and other hay imports.
文摘The objective of this work is to provide decision-making processes with an updated/real picture of the mobile resources in industrial environments through a constant feedback of information.The combination of identification technologies and wireless sensor networks(WSN) is proposed as a key development to guarantee an accurate and timely supply of online information regarding the localization and tracking of the mobile wireless devices.This approach uses a cooperative and distributed localization system,called ZigID,which is a WSN based on a Zigbee network with radio frequency identification(RFID) active tags as end nodes.The WSN can recover not only the ID information stored at the tags attached to mobile resources,but also any other useful data captured by specific sensors for acceleration,temperature,humidity and fuel status.This paper also shows the development of ZigID,including devices and information flows,as well as its implementation in ground handling operations at the Ciudad Real Central Airport,Spain.
基金the financial support from the National Natural Science Foundation of China(71473010,41701635)
文摘For studying new and renewable energy as a substitute for fossil energy in primary energy consumption and its impact on carbon emissions to cope with economic uncertainties, a multi-sector DSGE model was employed to simulate the dynamic impact on carbon emissions and macroeconomic development. The structural adjustment of energy consumption and the carbon emissions mitigation policy were considered in the model. The simulation results showed that using new and renewable energy instead of fossil energy is an optimal choice for the firms to comply with the regulations of carbon emission mitigation policy. Structural adjustment of energy consumption is the best route to achieve the dual goal of economic development and carbon emission reduction. Unexpected sharp fall in free carbon quota has a negative impact on the economy.
