This study investigates the role of financial literacy(FL),perceived access to finance(PAF),information communication technology(ICT)usage,and digitization in alleviating the level of credit constraint that micro,smal...This study investigates the role of financial literacy(FL),perceived access to finance(PAF),information communication technology(ICT)usage,and digitization in alleviating the level of credit constraint that micro,small,and medium enterprises(MSMEs)face in an emerging market.We draw on the economic research theories of human capital,knowledge-based view,and lifecycle hypothesis to explain the relationship between the variables.Using survey data collected from 333 MSME importers in Qatar—a country with heavy reliance on foreign goods—we find strong evidence that FL,PAF,ICT usage,and digitization are key determinants of Qatari MSME access to credit.In particular,PAF and FL are significant and have their expected signs in almost all the Probit regressions.For ICT usage and digitization,although they are key determinants of credit constraints,the findings are more sensitive and dependent on the type of financing and the resulting type of credit constraint.展开更多
This study investigates the impact of information communication technology(ICT),economic freedom,and economic sustainability on herding behavior,and examines whether the link between economic freedom and economic sust...This study investigates the impact of information communication technology(ICT),economic freedom,and economic sustainability on herding behavior,and examines whether the link between economic freedom and economic sustainability depends on ICT.Using quantile regression on a sample of seven Gulf Cooperation Council stock markets from 2004 to 2020,we find that ICT and economic freedom reduce herding in lower quantiles while promoting it in higher quantiles.Conversely,open market freedom and economic sustainability appear to correct herding in all quantiles.The results show that ICT reinforces the move away from herding seen with economic freedom for the transmission channel of ICT on herding.However,ICT plays a dual role in open market freedom and economic sustainability,weakening(strengthening)the curative effect of economic sustainability(open market freedom)in the lower quantiles and strengthening(weakening)it in higher quantiles.Thus,the highest impact in reducing herding exits through the combination of ICT and economic freedom is skewed to the lower quantiles with ICT-open market freedom and skewed to the upper quantiles with ICT-economic sustainability.These results offer substantial implications for policymakers.展开更多
The increase in the population as a whole gradually requires solving the issues of continuous development of the agro-industrial complex in all directions and components.This development is accompanied by an increase ...The increase in the population as a whole gradually requires solving the issues of continuous development of the agro-industrial complex in all directions and components.This development is accompanied by an increase in energy consumption,in the total balance of which electricity occupies a significant share.The purpose of this study is to develop a mathematical model of the use of infrared means for heating agro-industrial premises,which affects the formation of energy-saving and energy-saving processes of enterprises.The agrarian potential of Ukraine was analyzed and compared with other countries of the world for awareness,analysis and relevant conclusions regarding energy consumption and frugality.This helped,based on calculations and foreign experience,to prove the effectiveness of the proposed mathematical model.And its empiric results of application in the form of the use of a copper plate allowed to prove efficiency due to the reduction of electricity consumption in the conditions of maintaining the temperature regime of industrial-type premises not higher than 22–26°C when the equipment is operating at an output power of 40 W.The results of the research are the development of the existing theoretical foundations of ensuring the effective use of energy resources in agricultural organizations and can be used by economic entities and regional authorities for the purpose of making informed decisions in the field of energy-saving policy development in the agricultural sector.展开更多
Global climate change has created substantial difficulties in the areas of sustainability,development,and environmental conservation due to the widespread dependence on fossil fuels for energy production.Nevertheless,...Global climate change has created substantial difficulties in the areas of sustainability,development,and environmental conservation due to the widespread dependence on fossil fuels for energy production.Nevertheless,the promotion of renewable energy programs has the potential to significantly expedite endeavors aimed at tackling climate change.Thus,it is essential to conduct a thorough analysis that considers the financial aspects to fully understand the main hurdles that are preventing the advancement of renewable energy initiatives.Italy is a leading country in the worldwide deployment of renewable energy.The objective of this research is to assess the impact of financial growth,economic progress,and energy expenses on Italy’s adoption of renewable energy sources.By employing the Auto-Regressive Distributed Lag(ARDL)technique,we analyzed annual data spanning from1990 to 2022.Findings revealed that a 1%increase in financial and economic development would boost renewable energy consumption in the long run by 0.29%and 0.48%,respectively.Instead,a 1%increase in energy prices might reduce consumption of renewable energy by 0.05%in the long run.This study’s primary significance lies in furnishing actionable strategies for Italy to augment green finance for renewable energy,fostering sustained social and economic progress.Moreover,the analytical insights gleaned from this research offer valuable insights for energy-importing nations worldwide.展开更多
Corporate environmental sustainability has become a critical concern,particularly in resource-intensive industries such as pharmaceuticals,where regulatory pressures and stakeholder expectations continue to rise.Despi...Corporate environmental sustainability has become a critical concern,particularly in resource-intensive industries such as pharmaceuticals,where regulatory pressures and stakeholder expectations continue to rise.Despite increasing attention to green leadership,limited research has explored how environmentally responsible leadership(ERL)influences corporate environmental performance(CEP)through employee-driven sustainability behaviors.This study addresses this gap by examining the mediating roles of green knowledge-sharing behavior(GKSB),green innovative behavior(GIB),and voluntary green behavior(VGB),as well as the moderating role of green shared vision(GSV)in the ERL-CEP relationship.The study is grounded in Resource-Based View(RBV),Knowledge-Based View(KBV),Environmental-Based View(EBV),and Triple Bottom Line(TBL)theories,which collectively explain how leadership-driven sustainability efforts create long-term competitive advantages,drive environmental responsibility,and balance economic,social,and environmental sustainability.A quantitative research design was employed,using survey data from 384 employees in Bangladesh’s pharmaceutical sector.Data were analyzed using Partial Least Squares Structural Equation Modeling(PLS-SEM)in Smart-PLS 4.0 to assess direct,indirect,and moderating effects.The results confirm that ERL has a significant positive impact on CEP,with GKSB,GIB,and VGB acting as mediators,while GSV strengthens the ERL-CEP relationship.This study provides novel empirical evidence on the mechanisms linking green leadership to corporate sustainability,extending the application of RBV,KBV,EBV,and TBL to leadership-driven environmental management.The findings emphasize the importance of leadership training programs,sustainability-focused organizational cultures,and shared environmental visions.Policymakers should consider incentives for companies adopting ERL practices,ensuring that sustainability becomes a strategic,rather than compliance-driven,priority.This study contributes to leadership and sustainability literature by offering a comprehensive framework for integrating ERL into corporate governance and environmental strategies.展开更多
This study examines the impact of futures trading on market efficiency and price discovery in the U.S.real estate investment trusts(REITs)market.First,we present inconclusive evidence regarding efficiency improvement ...This study examines the impact of futures trading on market efficiency and price discovery in the U.S.real estate investment trusts(REITs)market.First,we present inconclusive evidence regarding efficiency improvement in the U.S.REIT spot market following the introduction of futures trading.To investigate the interplay between spot and futures markets,we analyze their respective roles in price discovery and find that,unlike in stock and bond markets,the spot market predominantly exhibits price leadership in the U.S.REITs market,despite the growing market size of futures.We find evidence that the limited role of futures in price discovery is associated with an increase in speculative demand,which outweighs hedging pressure.These findings suggest that policymakers should carefully monitor investor trading motives in the U.S.REITs market and consider revising market regulations to enhance liquidity,ensuring that increased liquidity does not primarily result from heightened speculative demand.展开更多
The traditional centralized data sharing systems have potential risks such as single point of failures and excessive working load on the central node.As a distributed and collaborative alternative,approaches based upo...The traditional centralized data sharing systems have potential risks such as single point of failures and excessive working load on the central node.As a distributed and collaborative alternative,approaches based upon blockchain have been explored recently for Internet of Things(IoTs).However,the access from a legitimate user may be denied without the pre-defined policy and data update on the blockchain could be costly to the owners.In this paper,we first address these issues by incorporating the Accountable Subgroup Multi-Signature(ASM)algorithm into the Attribute-based Access Control(ABAC)method with Policy Smart Contract,to provide a finegrained and flexible solution.Next,we propose a policy-based Chameleon Hash algorithm that allows the data to be updated in a reliable and convenient way by the authorized users.Finally,we evaluate our work by comparing its performance with the benchmarks.The results demonstrate significant improvement on the effectiveness and efficiency.展开更多
Earthen structures such as shore protection dikes and river embankments easily suffer from erosion under surface water runoff.This study made experimental efforts to explore the enzyme-induced carbonate precipitation(...Earthen structures such as shore protection dikes and river embankments easily suffer from erosion under surface water runoff.This study made experimental efforts to explore the enzyme-induced carbonate precipitation(EICP)method for slope erosion control under surface runoff for earthen structures.The sandy soils were treated by the EICP method for various rounds.Surface characteristics were evaluated by the surface penetration resistance,calcium carbonate content,and surface hard crust thickness of EICP-treated soils.Slope runoff erosion experiments were carried out to evaluate the erosion control performances of the EICP treatment.The surface penetration resistance,calcium carbonate content,and surface hard crust thickness were found to significantly increase with the treatment rounds.In the erosion experiments,it was observed that the level of damages decreased and the water flow volume required to trigger the damage increased with more treatments.The increase in the soil slope angle led to more serious surface damages.The amount and rate that the soil particles were eroded from the slope surfaces declined with more EICP treatments,which was consistent with those of visual observations.The preliminary investigations presented in this study have shown the potential of the EICP method for slope erosion control under surface runoff for earthen structures.展开更多
This paper considers a robust kernel regularized classification algorithm with a non-convex loss function which is proposed to alleviate the performance deterioration caused by the outliers.A comparison relationship b...This paper considers a robust kernel regularized classification algorithm with a non-convex loss function which is proposed to alleviate the performance deterioration caused by the outliers.A comparison relationship between the excess misclassification error and the excess generalization error is provided;from this,along with the convex analysis theory,a kind of learning rate is derived.The results show that the performance of the classifier is effected by the outliers,and the extent of impact can be controlled by choosing the homotopy parameters properly.展开更多
The effect of investor sentiment on stock volatility is a highly attractive research question in both the academic field and the real financial industry.With the proposal of China’s"dual carbon"target,green...The effect of investor sentiment on stock volatility is a highly attractive research question in both the academic field and the real financial industry.With the proposal of China’s"dual carbon"target,green stocks have gradually become an essential branch of Chinese stock markets.Focusing on 106 stocks from the new energy,environmental protection,and carbon–neutral sectors,we construct two investor sentiment proxies using Internet text and stock trading data,respectively.The Internet sentiment is based on posts from Eastmoney Guba,and the trading sentiment comes from a variety of trading indicators.In addition,we divide the realized volatility into continuous and jump parts,and then investigate the effects of investor sentiment on different types of volatilities.Our empirical findings show that both sentiment indices impose significant positive impacts on realized,continuous,and jump volatilities,where trading sentiment is the main factor.We further explore the mediating effect of information asymmetry,measured by the volume-synchronized probability of informed trading(VPIN),on the path of investor sentiment affecting stock volatility.It is evidenced that investor sentiments are positively correlated with the VPIN,and they can affect volatilities through the VPIN.We then divide the total sample around the coronavirus disease 2019(COVID-19)pandemic.The empirical results reveal that the market volatility after the COVID-19 pandemic is more susceptible to investor sentiments,especially to Internet sentiment.Our study is of great significance for maintaining the stability of green stock markets and reducing market volatility.展开更多
This paper proposes numerical methods for solving hybrid weakly singular integro-differential equations of the second kind. The terms in these equations are in the following order: derivative term of a state, integro-...This paper proposes numerical methods for solving hybrid weakly singular integro-differential equations of the second kind. The terms in these equations are in the following order: derivative term of a state, integro-differential term of a state with a weakly singular kernel, a state, integral term of a state with a smooth kernel, and force. The original class of weakly singular integro-differential equations of the first kind is derived from aeroelasticity mathematical models. Among the proposed methods, the method for solving linear cases is fully based on previously reported approximation scheme for equations of the first kind. For nonlinear cases, a revised method is proposed. Examples are presented to demonstrate the effectiveness of the proposed methods, and the results indicate that the proposed methods facilitate achieving satisfactory and accurate approximations.展开更多
This study presents numerical algorithms for solving a class of equations that partly consists of derivatives of the unknown state at previous certain times, as well as an integro-differential term containing a weakly...This study presents numerical algorithms for solving a class of equations that partly consists of derivatives of the unknown state at previous certain times, as well as an integro-differential term containing a weakly singular kernel. These equations are types of integro-differential equation of the second kind and were originally obtained from an aeroelasticity problem. One of the main contributions of this study is to propose numerical algorithms that do not involve transforming the original equation into the corresponding Volterra equation, but still enable the numerical solution of the original equation to be determined. The feasibility of the proposed numerical algorithm is demonstrated by applying examples in measuring the maximum errors with exact solutions at every computed nodes and calculating the corresponding numerical rates of convergence thereafter.展开更多
The challenge of achieving sustainable economic development with a secure environmental system is a global challenge faced by both developed and developing countries.Energy Efficiency(EE)is crucial in achieving sustai...The challenge of achieving sustainable economic development with a secure environmental system is a global challenge faced by both developed and developing countries.Energy Efficiency(EE)is crucial in achieving sustainable economic growth while reducing ecological impacts.This research utilizes the Slack-Based Measure Data Envelopment Analysis(SBM-DEA)and the Malmquist-Luenberger Index(MLI)method to evaluate EE and productivity changes from 1995 to 2020 across G20 countries.The study uses four different input-output bundles to gauge the impact of renewable and non-renewable energy consumption and carbon emissions on EE and productivity changes.The study results show that including renewable energy consumption improves the average EE from 0.783 to 0.8578,but energy productivity declines from 1.0064 to 0.9988.Incorporating bad output(carbon emissions)in the estimation process enhances renewable EE and productivity change,resulting in an average EE of 0.6678 and MLI of 1.0044.Technological change is identified as the primary determinant of energy productivity growth in scenarios 1 and 2,while technical efficiency determines energy productivity change in scenarios 3 and 4.The Kruskal-Wallis test reveals a significant statistical difference between the mean EE and MLI scores of G20 countries.展开更多
This paper aims to develop a power penalty method for a linear parabolic variational inequality （VI） in two spatial dimensions governing the two-asset American option valuation. This method yields a two-dimensional ...This paper aims to develop a power penalty method for a linear parabolic variational inequality （VI） in two spatial dimensions governing the two-asset American option valuation. This method yields a two-dimensional nonlinear parabolic PDE containing a power penalty term with penalty constant λ〉 1 and a power parameter k 〉 0. We show that the nonlinear PDE is uniquely solvable and the solution of the PDE converges to that of the VI at the rate of order O（λ^-k/2）. A fitted finite volume method is designed to solve the nonlinear PDE, and some numerical experiments are performed to illustrate the usefulness of this method.展开更多
Marx's theory of natural force resources is an indispensable part of Marx's economic theory.Natural force resources,as a kind of natural elements that do not cost a penny,are added to the production process fr...Marx's theory of natural force resources is an indispensable part of Marx's economic theory.Natural force resources,as a kind of natural elements that do not cost a penny,are added to the production process free of charge,and play a special role in the production process.Grasping and understanding the scientific connotation of Marx's theory of natural force resources is of great theoretical value and practical significance for promoting the harmonious unity of man and nature and adhering to the strategy of sustainable economic development.展开更多
This study analyzes the impact of petroleum and non-petroleum indices on the financial development of the Sultanate of Oman from 1978 to 2017.To this end,it uses the petroleum proxy of oil rents(%of gross domestic pro...This study analyzes the impact of petroleum and non-petroleum indices on the financial development of the Sultanate of Oman from 1978 to 2017.To this end,it uses the petroleum proxy of oil rents(%of gross domestic product,GDP)and the non-petroleum proxy of industry(including construction)value added(%of GDP);agriculture,forestry,and fishing value added(%of GDP);and services value added(%of GDP)to determine the effect on financial development,measured by the amount of domestic credit extended to the private sector by banks(%of GDP).It applies an autoregressive distributed lag(ARDL)model.The long-term equation illustrates that the agriculture and industry GDPs have a negative and significant relationship with domestic credit in Oman.However,the oil and service sector GDPs promote financial development.The short-term equation illustrates that the oil,agricultural,and service sectors have positive and significant effects on domestic credit.The conclusion is that the economy of Oman is still in the first phase of economic diversification.Accordingly,the government should use oil revenues to develop various non-oil industrial sectors.This would enhance the country’s competitiveness in the global economy and positively contribute to improving the liquidity of the banking sector for stimulating credit at the macroeconomic level.展开更多
Marx's theory of scientific and technological progress and utilization of natural resources is an indispensable and important part of Marx's economic theory.To realize the harmonious unification of man and nat...Marx's theory of scientific and technological progress and utilization of natural resources is an indispensable and important part of Marx's economic theory.To realize the harmonious unification of man and nature,man must correctly understand the effect of scientific and technological progress on the use of natural resources,fundamentally solve the problem that scientific and technological progress cannot replace the position of natural resources in economic development,and objectively evaluate the relationship between human power and the power of nature.Grasping and comprehending the scientific connotation of Marx's theory of scientific and technological progress and utilization of natural resources has a very important theoretical value and practical significance for saving and effectively using natural resources and building an environment-friendly society.展开更多
As an innovation mode of organization, technology alliance has being increasingly paid more attention to by more and more small and medium-sized enterprises （SME）. In this paper, on the basis of analyzing the theory...As an innovation mode of organization, technology alliance has being increasingly paid more attention to by more and more small and medium-sized enterprises （SME）. In this paper, on the basis of analyzing the theory and practice meaning of the technology alliance, cooperative game method is used to analyze the forming process of the cooperative mechanism, and it points out that cooperation will make both sides get the largest benefits.展开更多
With the development of the economy in China,the regionalization of China Yuan is accelerated. This paper analyzes the existing conditions of the regionalization of China Yuan in ASEAN theoretically and practically,po...With the development of the economy in China,the regionalization of China Yuan is accelerated. This paper analyzes the existing conditions of the regionalization of China Yuan in ASEAN theoretically and practically,points out the restricting factors and puts forward the path of the regionalization of China Yuan in ASEAN — with Singapore,Thailand,Malaysia and Indonesia being the pilot countries and realizing regionalization of China Yuan in ASEAN gradually.展开更多
基金supported by QNRF under the Grant Number NPRP11C-1229-170007 from the Qatar National Research Fund(a member of Qatar foundation).
文摘This study investigates the role of financial literacy(FL),perceived access to finance(PAF),information communication technology(ICT)usage,and digitization in alleviating the level of credit constraint that micro,small,and medium enterprises(MSMEs)face in an emerging market.We draw on the economic research theories of human capital,knowledge-based view,and lifecycle hypothesis to explain the relationship between the variables.Using survey data collected from 333 MSME importers in Qatar—a country with heavy reliance on foreign goods—we find strong evidence that FL,PAF,ICT usage,and digitization are key determinants of Qatari MSME access to credit.In particular,PAF and FL are significant and have their expected signs in almost all the Probit regressions.For ICT usage and digitization,although they are key determinants of credit constraints,the findings are more sensitive and dependent on the type of financing and the resulting type of credit constraint.
文摘This study investigates the impact of information communication technology(ICT),economic freedom,and economic sustainability on herding behavior,and examines whether the link between economic freedom and economic sustainability depends on ICT.Using quantile regression on a sample of seven Gulf Cooperation Council stock markets from 2004 to 2020,we find that ICT and economic freedom reduce herding in lower quantiles while promoting it in higher quantiles.Conversely,open market freedom and economic sustainability appear to correct herding in all quantiles.The results show that ICT reinforces the move away from herding seen with economic freedom for the transmission channel of ICT on herding.However,ICT plays a dual role in open market freedom and economic sustainability,weakening(strengthening)the curative effect of economic sustainability(open market freedom)in the lower quantiles and strengthening(weakening)it in higher quantiles.Thus,the highest impact in reducing herding exits through the combination of ICT and economic freedom is skewed to the lower quantiles with ICT-open market freedom and skewed to the upper quantiles with ICT-economic sustainability.These results offer substantial implications for policymakers.
文摘The increase in the population as a whole gradually requires solving the issues of continuous development of the agro-industrial complex in all directions and components.This development is accompanied by an increase in energy consumption,in the total balance of which electricity occupies a significant share.The purpose of this study is to develop a mathematical model of the use of infrared means for heating agro-industrial premises,which affects the formation of energy-saving and energy-saving processes of enterprises.The agrarian potential of Ukraine was analyzed and compared with other countries of the world for awareness,analysis and relevant conclusions regarding energy consumption and frugality.This helped,based on calculations and foreign experience,to prove the effectiveness of the proposed mathematical model.And its empiric results of application in the form of the use of a copper plate allowed to prove efficiency due to the reduction of electricity consumption in the conditions of maintaining the temperature regime of industrial-type premises not higher than 22–26°C when the equipment is operating at an output power of 40 W.The results of the research are the development of the existing theoretical foundations of ensuring the effective use of energy resources in agricultural organizations and can be used by economic entities and regional authorities for the purpose of making informed decisions in the field of energy-saving policy development in the agricultural sector.
文摘Global climate change has created substantial difficulties in the areas of sustainability,development,and environmental conservation due to the widespread dependence on fossil fuels for energy production.Nevertheless,the promotion of renewable energy programs has the potential to significantly expedite endeavors aimed at tackling climate change.Thus,it is essential to conduct a thorough analysis that considers the financial aspects to fully understand the main hurdles that are preventing the advancement of renewable energy initiatives.Italy is a leading country in the worldwide deployment of renewable energy.The objective of this research is to assess the impact of financial growth,economic progress,and energy expenses on Italy’s adoption of renewable energy sources.By employing the Auto-Regressive Distributed Lag(ARDL)technique,we analyzed annual data spanning from1990 to 2022.Findings revealed that a 1%increase in financial and economic development would boost renewable energy consumption in the long run by 0.29%and 0.48%,respectively.Instead,a 1%increase in energy prices might reduce consumption of renewable energy by 0.05%in the long run.This study’s primary significance lies in furnishing actionable strategies for Italy to augment green finance for renewable energy,fostering sustained social and economic progress.Moreover,the analytical insights gleaned from this research offer valuable insights for energy-importing nations worldwide.
文摘Corporate environmental sustainability has become a critical concern,particularly in resource-intensive industries such as pharmaceuticals,where regulatory pressures and stakeholder expectations continue to rise.Despite increasing attention to green leadership,limited research has explored how environmentally responsible leadership(ERL)influences corporate environmental performance(CEP)through employee-driven sustainability behaviors.This study addresses this gap by examining the mediating roles of green knowledge-sharing behavior(GKSB),green innovative behavior(GIB),and voluntary green behavior(VGB),as well as the moderating role of green shared vision(GSV)in the ERL-CEP relationship.The study is grounded in Resource-Based View(RBV),Knowledge-Based View(KBV),Environmental-Based View(EBV),and Triple Bottom Line(TBL)theories,which collectively explain how leadership-driven sustainability efforts create long-term competitive advantages,drive environmental responsibility,and balance economic,social,and environmental sustainability.A quantitative research design was employed,using survey data from 384 employees in Bangladesh’s pharmaceutical sector.Data were analyzed using Partial Least Squares Structural Equation Modeling(PLS-SEM)in Smart-PLS 4.0 to assess direct,indirect,and moderating effects.The results confirm that ERL has a significant positive impact on CEP,with GKSB,GIB,and VGB acting as mediators,while GSV strengthens the ERL-CEP relationship.This study provides novel empirical evidence on the mechanisms linking green leadership to corporate sustainability,extending the application of RBV,KBV,EBV,and TBL to leadership-driven environmental management.The findings emphasize the importance of leadership training programs,sustainability-focused organizational cultures,and shared environmental visions.Policymakers should consider incentives for companies adopting ERL practices,ensuring that sustainability becomes a strategic,rather than compliance-driven,priority.This study contributes to leadership and sustainability literature by offering a comprehensive framework for integrating ERL into corporate governance and environmental strategies.
基金supported by the National Research Foundation of Korea funded by the Ministry of Science and ICT(2022R1A2C1004258:Kwangwon Ahn)the Sogang University Research Grant of 2023(No.202310016.01:Sungbin Sohn).
文摘This study examines the impact of futures trading on market efficiency and price discovery in the U.S.real estate investment trusts(REITs)market.First,we present inconclusive evidence regarding efficiency improvement in the U.S.REIT spot market following the introduction of futures trading.To investigate the interplay between spot and futures markets,we analyze their respective roles in price discovery and find that,unlike in stock and bond markets,the spot market predominantly exhibits price leadership in the U.S.REITs market,despite the growing market size of futures.We find evidence that the limited role of futures in price discovery is associated with an increase in speculative demand,which outweighs hedging pressure.These findings suggest that policymakers should carefully monitor investor trading motives in the U.S.REITs market and consider revising market regulations to enhance liquidity,ensuring that increased liquidity does not primarily result from heightened speculative demand.
基金supported by the National Natural Science Foundation of China under Grant 61972148。
文摘The traditional centralized data sharing systems have potential risks such as single point of failures and excessive working load on the central node.As a distributed and collaborative alternative,approaches based upon blockchain have been explored recently for Internet of Things(IoTs).However,the access from a legitimate user may be denied without the pre-defined policy and data update on the blockchain could be costly to the owners.In this paper,we first address these issues by incorporating the Accountable Subgroup Multi-Signature(ASM)algorithm into the Attribute-based Access Control(ABAC)method with Policy Smart Contract,to provide a finegrained and flexible solution.Next,we propose a policy-based Chameleon Hash algorithm that allows the data to be updated in a reliable and convenient way by the authorized users.Finally,we evaluate our work by comparing its performance with the benchmarks.The results demonstrate significant improvement on the effectiveness and efficiency.
基金supported by the National Na-tural Science Foundation of China(Nos.51978244,51979088,52078188 and 51879246).
文摘Earthen structures such as shore protection dikes and river embankments easily suffer from erosion under surface water runoff.This study made experimental efforts to explore the enzyme-induced carbonate precipitation(EICP)method for slope erosion control under surface runoff for earthen structures.The sandy soils were treated by the EICP method for various rounds.Surface characteristics were evaluated by the surface penetration resistance,calcium carbonate content,and surface hard crust thickness of EICP-treated soils.Slope runoff erosion experiments were carried out to evaluate the erosion control performances of the EICP treatment.The surface penetration resistance,calcium carbonate content,and surface hard crust thickness were found to significantly increase with the treatment rounds.In the erosion experiments,it was observed that the level of damages decreased and the water flow volume required to trigger the damage increased with more treatments.The increase in the soil slope angle led to more serious surface damages.The amount and rate that the soil particles were eroded from the slope surfaces declined with more EICP treatments,which was consistent with those of visual observations.The preliminary investigations presented in this study have shown the potential of the EICP method for slope erosion control under surface runoff for earthen structures.
基金supported by the NSF(61877039)the NSFC/RGC Joint Research Scheme(12061160462 and N City U 102/20)of China+2 种基金the NSF(LY19F020013)of Zhejiang Provincethe Special Project for Scientific and Technological Cooperation(20212BDH80021)of Jiangxi Provincethe Science and Technology Project in Jiangxi Province Department of Education(GJJ211334)。
文摘This paper considers a robust kernel regularized classification algorithm with a non-convex loss function which is proposed to alleviate the performance deterioration caused by the outliers.A comparison relationship between the excess misclassification error and the excess generalization error is provided;from this,along with the convex analysis theory,a kind of learning rate is derived.The results show that the performance of the classifier is effected by the outliers,and the extent of impact can be controlled by choosing the homotopy parameters properly.
基金supported by the National Natural Science Foundation of China(72171005),to which we are deeply grateful。
文摘The effect of investor sentiment on stock volatility is a highly attractive research question in both the academic field and the real financial industry.With the proposal of China’s"dual carbon"target,green stocks have gradually become an essential branch of Chinese stock markets.Focusing on 106 stocks from the new energy,environmental protection,and carbon–neutral sectors,we construct two investor sentiment proxies using Internet text and stock trading data,respectively.The Internet sentiment is based on posts from Eastmoney Guba,and the trading sentiment comes from a variety of trading indicators.In addition,we divide the realized volatility into continuous and jump parts,and then investigate the effects of investor sentiment on different types of volatilities.Our empirical findings show that both sentiment indices impose significant positive impacts on realized,continuous,and jump volatilities,where trading sentiment is the main factor.We further explore the mediating effect of information asymmetry,measured by the volume-synchronized probability of informed trading(VPIN),on the path of investor sentiment affecting stock volatility.It is evidenced that investor sentiments are positively correlated with the VPIN,and they can affect volatilities through the VPIN.We then divide the total sample around the coronavirus disease 2019(COVID-19)pandemic.The empirical results reveal that the market volatility after the COVID-19 pandemic is more susceptible to investor sentiments,especially to Internet sentiment.Our study is of great significance for maintaining the stability of green stock markets and reducing market volatility.
文摘This paper proposes numerical methods for solving hybrid weakly singular integro-differential equations of the second kind. The terms in these equations are in the following order: derivative term of a state, integro-differential term of a state with a weakly singular kernel, a state, integral term of a state with a smooth kernel, and force. The original class of weakly singular integro-differential equations of the first kind is derived from aeroelasticity mathematical models. Among the proposed methods, the method for solving linear cases is fully based on previously reported approximation scheme for equations of the first kind. For nonlinear cases, a revised method is proposed. Examples are presented to demonstrate the effectiveness of the proposed methods, and the results indicate that the proposed methods facilitate achieving satisfactory and accurate approximations.
文摘This study presents numerical algorithms for solving a class of equations that partly consists of derivatives of the unknown state at previous certain times, as well as an integro-differential term containing a weakly singular kernel. These equations are types of integro-differential equation of the second kind and were originally obtained from an aeroelasticity problem. One of the main contributions of this study is to propose numerical algorithms that do not involve transforming the original equation into the corresponding Volterra equation, but still enable the numerical solution of the original equation to be determined. The feasibility of the proposed numerical algorithm is demonstrated by applying examples in measuring the maximum errors with exact solutions at every computed nodes and calculating the corresponding numerical rates of convergence thereafter.
文摘The challenge of achieving sustainable economic development with a secure environmental system is a global challenge faced by both developed and developing countries.Energy Efficiency(EE)is crucial in achieving sustainable economic growth while reducing ecological impacts.This research utilizes the Slack-Based Measure Data Envelopment Analysis(SBM-DEA)and the Malmquist-Luenberger Index(MLI)method to evaluate EE and productivity changes from 1995 to 2020 across G20 countries.The study uses four different input-output bundles to gauge the impact of renewable and non-renewable energy consumption and carbon emissions on EE and productivity changes.The study results show that including renewable energy consumption improves the average EE from 0.783 to 0.8578,but energy productivity declines from 1.0064 to 0.9988.Incorporating bad output(carbon emissions)in the estimation process enhances renewable EE and productivity change,resulting in an average EE of 0.6678 and MLI of 1.0044.Technological change is identified as the primary determinant of energy productivity growth in scenarios 1 and 2,while technical efficiency determines energy productivity change in scenarios 3 and 4.The Kruskal-Wallis test reveals a significant statistical difference between the mean EE and MLI scores of G20 countries.
文摘This paper aims to develop a power penalty method for a linear parabolic variational inequality （VI） in two spatial dimensions governing the two-asset American option valuation. This method yields a two-dimensional nonlinear parabolic PDE containing a power penalty term with penalty constant λ〉 1 and a power parameter k 〉 0. We show that the nonlinear PDE is uniquely solvable and the solution of the PDE converges to that of the VI at the rate of order O（λ^-k/2）. A fitted finite volume method is designed to solve the nonlinear PDE, and some numerical experiments are performed to illustrate the usefulness of this method.
文摘Marx's theory of natural force resources is an indispensable part of Marx's economic theory.Natural force resources,as a kind of natural elements that do not cost a penny,are added to the production process free of charge,and play a special role in the production process.Grasping and understanding the scientific connotation of Marx's theory of natural force resources is of great theoretical value and practical significance for promoting the harmonious unity of man and nature and adhering to the strategy of sustainable economic development.
文摘This study analyzes the impact of petroleum and non-petroleum indices on the financial development of the Sultanate of Oman from 1978 to 2017.To this end,it uses the petroleum proxy of oil rents(%of gross domestic product,GDP)and the non-petroleum proxy of industry(including construction)value added(%of GDP);agriculture,forestry,and fishing value added(%of GDP);and services value added(%of GDP)to determine the effect on financial development,measured by the amount of domestic credit extended to the private sector by banks(%of GDP).It applies an autoregressive distributed lag(ARDL)model.The long-term equation illustrates that the agriculture and industry GDPs have a negative and significant relationship with domestic credit in Oman.However,the oil and service sector GDPs promote financial development.The short-term equation illustrates that the oil,agricultural,and service sectors have positive and significant effects on domestic credit.The conclusion is that the economy of Oman is still in the first phase of economic diversification.Accordingly,the government should use oil revenues to develop various non-oil industrial sectors.This would enhance the country’s competitiveness in the global economy and positively contribute to improving the liquidity of the banking sector for stimulating credit at the macroeconomic level.
文摘Marx's theory of scientific and technological progress and utilization of natural resources is an indispensable and important part of Marx's economic theory.To realize the harmonious unification of man and nature,man must correctly understand the effect of scientific and technological progress on the use of natural resources,fundamentally solve the problem that scientific and technological progress cannot replace the position of natural resources in economic development,and objectively evaluate the relationship between human power and the power of nature.Grasping and comprehending the scientific connotation of Marx's theory of scientific and technological progress and utilization of natural resources has a very important theoretical value and practical significance for saving and effectively using natural resources and building an environment-friendly society.
文摘As an innovation mode of organization, technology alliance has being increasingly paid more attention to by more and more small and medium-sized enterprises （SME）. In this paper, on the basis of analyzing the theory and practice meaning of the technology alliance, cooperative game method is used to analyze the forming process of the cooperative mechanism, and it points out that cooperation will make both sides get the largest benefits.
基金the staged achievement of the scientific research project of Beijing Language and Culture University(funded by basic scientific research of central colleges and universities)(15YJ0403)
文摘With the development of the economy in China,the regionalization of China Yuan is accelerated. This paper analyzes the existing conditions of the regionalization of China Yuan in ASEAN theoretically and practically,points out the restricting factors and puts forward the path of the regionalization of China Yuan in ASEAN — with Singapore,Thailand,Malaysia and Indonesia being the pilot countries and realizing regionalization of China Yuan in ASEAN gradually.
