Unimpeded trade is one of the cooperation priorities in the Belt and Road Initiative proposed by China. On 15 May 2017, the Joint Communique of the Leaders Roundtable of the Belt and Road Forum for International Coope...Unimpeded trade is one of the cooperation priorities in the Belt and Road Initiative proposed by China. On 15 May 2017, the Joint Communique of the Leaders Roundtable of the Belt and Road Forum for International Cooperation reaffirmed the participants＇ shared commitment to build an open economy and ensure free and inclusive trade. The Belt and Road Initiative （BRI） is not only China＇s new action to drive its open and global develoPment, but also a platform for an increasing number of countries to explore free and inclusive trade and promote a universal, rule-based, open, non-discriminatory, and equitable multilateral trade system. It is therefore important to examine BRI and global trade networks. More specifically, the topological relationship between the this article first analyzes the community structure of trade networks using a community detection algorithm, and then estimates the topological relationship between different trade communities. The findings of this article are as follows. First, this research identified three trade communities and two sub-communities in the BRI trade network, in which China is the core, Russia is the sub-core of the biggest trade community, and India, United Arab Emirates, and Saudi Arabia are cores of the second trade community （South Asia-West Asia）. Second, it identified five trade communities in the global trade network, centred on China, USA, Russia, India-United Arab Emirates, and Ger- many-Netherlands-France-Britain and other European developed countries. Third, the topo- logical analysis indicated that in the global trade network, most BRI countries are attracted by the core nodes of the BRI regions, such as the China, Russia and India-United Arab Emirates core nodes, and have strong trade contacts with BRI countries. Most Central-East European countries are mainly attracted by Germany-Netherlands-France-Britain and other developed European countries with a low penetration of BRI trade. Although some Southeast Asian countries are incorporated into the Asia-Australia-South Africa community with China as the core, they still need to strengthen trade linkages with BRI countries.展开更多
As a global strategic reserve resource,rare earth has been widely used in important industries,such as military equipment and biomedicine.However,existing analyses based solely on the total volume of rare earth trade ...As a global strategic reserve resource,rare earth has been widely used in important industries,such as military equipment and biomedicine.However,existing analyses based solely on the total volume of rare earth trade fail to uncover the underlying competition and dependency dynamics.To address this gap,this paper employs the principles of trade preference and import similarity to construct dependency and competition networks.Complex network analysis is then employed to study the evolution of the global rare earth trade network from 2002 to 2018.The main conclusions are as follows.The global rare earth trade follows the Pareto principle,and the trade network shows a scale-free distribution.China has emerged as the world’s largest importer and exporter of rare earth since 2017.In the dependency network,China has become the most dependent country since 2006.The result of community division shows that China has separated from the American community and formed new communities with the Association of Southeast Asian Nations(ASEAN)countries.The United States of America has formed a super-strong community with European and Asian countries.In the competition network,the distribution of competition intensity follows a scale-free distribution.Most countries face low-intensity competition,but there are numerous competing countries.The competition related to China has increased significantly.Lastly,the competition source for the United States of America has shifted from Mexico to China,resulting in China,the USA,and Japan becoming the core participants in the competition network.展开更多
The production and trade of primary products had a growing impact on the economic security of all countries and regions,and the strategic position of these products in the global trade network was becoming increasingl...The production and trade of primary products had a growing impact on the economic security of all countries and regions,and the strategic position of these products in the global trade network was becoming increasingly prominent.Based on complex network theory,this paper explored the spatial pattern and complex structural evolution of the global primary product trade network(GPPTN)during 1985-2015 by using index methods,such as centrality,Sankey diagram,and structure entropy,focusing on the diversified spatial structure of China’s import and export markets for primary products(with exceptions of Taiwan of China,Hong Kong of China,and Macao of China due to a lack of data)and their geographical implications for China’s energy security.The research offered the following key findings.The GPPTN showed an obvious spatial heterogeneity pattern,and the area of import consumption was more concentrated;however,the overall trend was decentralized.The trade center of gravity shifted eastwards and reflected the rise of emerging markets.The overall flow of the GPPTN was from west to east and from south to north.In terms of the community detection of the GPPTN,North America,Europe,and Asia increasingly presented an unbalanced“tripartite confrontation”.China’s exports of primary products were mainly concentrated in the Association of Southeast Asian Nations(ASEAN)and other peripheral regions of Asia,and its imports undergone a major transformation,gradually expanding from the peripheral regions of Asia to Africa,the Middle East,Latin America,and other parts of the world.Energy fuels also became the largest imported primary products.Based on the changing trend of structural entropy and main market share,the analysis showed that the stable supply of China’s energy diversification was gradually realized.In particular,the cooperation dividend proposed by the Belt and Road initiative became an important turning point and a strong support for the expansion of China’s energy market diversification pattern and guarantee of energy security.展开更多
The economic potential induced by environmental changes in the Arctic region garnered substantial interest,which positions Arctic trade as a crucial indicator in forecasting the impacts of climate change on the global...The economic potential induced by environmental changes in the Arctic region garnered substantial interest,which positions Arctic trade as a crucial indicator in forecasting the impacts of climate change on the global economy.Nevertheless,attention devoted to the evolving dynamics of trade in the Arctic region remains scarce.In this study,we constructed export trade network in the Arctic region(including Denmark,Finland,Sweden,Norway,Iceland,the Canadian Arctic,the Russian Arctic,Alaska State of the USA,and Greenland)from 1990 to 2019 and analyzed its topology and evolutionary characteristics through complex network theory.We used a structural entropy index based on the distribution of the number of trading partners and the degree of trade concentration to assess export diversity,while we also utilized a revealed comparative advantage index to evaluate product export competitiveness using the share of trade volume of each type of product.The results indicate that the total export trade in the Arctic region increased by 53.4%during 1990-2019,with the most significant growth observed in the exports of chemical products and mineral fuels.The increasing complexity of trade network in the Arctic region resulted in the region’s export destinations no longer being concentrated on a few major countries and regions.The proportion of exports from the Arctic region to Europe decreased by 13.5%,while the proportion of exports from the Arctic region to Asia and North America increased by 6.8%and 3.1%,respectively.The Arctic region exhibited clear distinctions in the range of flows of different products,and its export trade was becoming increasingly diversified.Although differences in comparative advantages between products within individual countries or regions have narrowed,substantial gaps persist.The findings of this study can enhance the comprehensive understanding of the significance and function of Arctic trade activities within the global economy,providing a scientific basis for addressing the associated challenges and opportunities in the context of climate change.展开更多
"Ensuring stability in foreign trade"and"ensuring food security"are essential parts of China's"six priorities"and"stability in six areas".Based on the data of bilateral food..."Ensuring stability in foreign trade"and"ensuring food security"are essential parts of China's"six priorities"and"stability in six areas".Based on the data of bilateral food trade between countries during 1996-2018,using descriptive statistical analysis and social network analysis methods,this paper analyzed the changes of China's trade position in the world food trade network.It reached the following results.(i)China's position in the trade network has undergone a phased process of"remarkable improvement-continuous fluctuation-significant decline-steady growth".(ii)Export participation is better than import participation,the gap between trade export strength and import strength is widening,and the effective scale and constraint index gradually improve.(iii)The change of China's position in the food trade network is affected by geographical,economic,institutional and cultural factors.In view of these findings,it is recommended to improve node centrality,enhance network participation,improve network interconnection,and prevent international market risks,so as to better deal with the complex international environment.展开更多
Both farmers and traders benefit from trade networking, which is crucial for the local economy. Therefore, it is crucial to understand how these networks operate, and how they can be managed more effectively. Througho...Both farmers and traders benefit from trade networking, which is crucial for the local economy. Therefore, it is crucial to understand how these networks operate, and how they can be managed more effectively. Throughout this study, we examine the economic networks formed between farmers and traders through the trade of food products. These networks are analyzed from the perspective of their structure and the factors that influence their development. Using data from 18 farmers and 15 traders, we applied exponential random graph models. The results of our study showed that connectivity, Popularity Spread, activity spread, good transportation systems, and high yields all affected the development of networks. Therefore, farmers’ productivity and high market demand can contribute to local food-crop trade. The network was not affected by reciprocity, open markets, proximity to locations, or trade experience of actors. Policy makers should consider these five factors when formulating policies for local food-crop trade. Additionally, local actors should be encouraged to use these factors to improve their network development. However, it is important to note that these factors alone cannot guarantee success. Policy makers and actors must also consider other factors such as legal frameworks, economic policies, and resource availability. Our approach can be used in future research to determine how traders and farmers can enhance productivity and profit in West Africa. This study addresses a research gap by examining factors influencing local food trade in a developing country.展开更多
[Purpose]Global economic integration has intensified cereal trade,reshaping China’s grain security.Strengthening China’s role in the global cereal trade network is vital for improving trade patterns and safeguarding...[Purpose]Global economic integration has intensified cereal trade,reshaping China’s grain security.Strengthening China’s role in the global cereal trade network is vital for improving trade patterns and safeguarding food security.[Design]Using bilateral trade data for eight major cereals in over 200 countries(1990–2021),this study applies social network analysis to construct global trade networks,measure key indicators,and visualize structural changes with Gephi.[Findings]From 1990 to 2021,average node degrees rose,with North America,Europe,and Australia as core hubs.Node degrees follow a power-law distribution,network density increased,clustering coefficients remained stable,and path lengths showed an inverted“U”trend.The network is moving toward decentralization and diversification.[Originality]By combining micro-level cereal trade analysis with social network methods,this study depicts the evolution of global trade structures,tracks China’s shifting position,and suggests new directions for national food security.展开更多
ymmetry of the world trade network provides a novel perspective to understand the world-wide trading system. However, symmetry in the world trade network （WTN） has been rarely studied so far. In this paper, the auth...ymmetry of the world trade network provides a novel perspective to understand the world-wide trading system. However, symmetry in the world trade network （WTN） has been rarely studied so far. In this paper, the authors systematically explore the symmetry in WTN. The authors construct WTN in 2005 and explore the size and structure of its automorphism group, through which the authors find that WTN is symmetric, particularly, locally symmetric to a certain degree. Furthermore, the authors work out the symmetric motifs of WTN and investigate the structure and function of the symmetric motifs, coming to the conclusion that local symmetry will have great effect on the stability of the WTN and that continuous symmetry-breakings will generate complexity and diversity of the trade network. Finally, utilizing the local symmetry of the network, the authors work out the quotient of WTN, which is the structural skeleton dominating stability and evolution of WTN.展开更多
Pesticides are agricultural inputs that can significantly reduce yield losses,regulate plant growth,effectively liberate agricultural productivity,and improve food security.The availability of pesticides in economies ...Pesticides are agricultural inputs that can significantly reduce yield losses,regulate plant growth,effectively liberate agricultural productivity,and improve food security.The availability of pesticides in economies worldwide is ensured by redistribution through international trade,with different economies playing different roles in this process.In this study,we measured and ranked the importance of economies using nine node metrics.We found that the clustering coefficient was negatively correlated with the other eight node metrics,whereas the other eight node metrics were positively correlated with each other and could be grouped into three communities(betweenness;in-degree,PageRank,authority,and in-closeness;out-degree,hub,and out-closeness).We further investigated the structural robustness of international pesticide trade networks proxied by large component size under three types of shocks to economies(node removal in descending,random,and ascending orders).The results showed that,except for the clustering coefficient,international pesticide trade networks are relatively robust under shocks to economies in ascending order but fragile under shocks to economies in descending order.By contrast,removing nodes with a clustering coefficient in ascending and descending order yielded similar robustness curves.Moreover,the structural robustness related to large component size evolved over time and exhibited an inverse U-shaped pattern.展开更多
As the main food source for humans, the global movement of the three major grains significantly impacts human survival and development. To investigate the evolution of the world cereal trade network and its developmen...As the main food source for humans, the global movement of the three major grains significantly impacts human survival and development. To investigate the evolution of the world cereal trade network and its development trend, a weighted directed dynamic multiplexed network was established using historical data on cereal trade, cereal import dependency ratio, and arable land per capita. Inspired by the MLP framework, we redefined the weight determination method for computing layer weights and edge weights of the target layer, modified the CN, RA, AA, and PA indicators, and proposed the node similarity indicator for weighted directed networks. The AUC metric, which measures the accuracy of the algorithm, has also been improved in order to finally obtain the link prediction results for the grain trading network. The prediction results were processed, such as web-based presentation and community partition. It was found that the number of generalized trade agreements does not have a decisive impact on inter-country cereal trade. The former large grain exporters continue to play an important role in this trade network. In the future, the world trade in cereals will develop in the direction of more frequent intercontinental trade and gradually weaken the intracontinental cereal trade.展开更多
With the rapid development of the Internet and information technology,network trade has emerged and broken through the traditional trade boundaries in the rapidly developing information technology.Therefore,with the a...With the rapid development of the Internet and information technology,network trade has emerged and broken through the traditional trade boundaries in the rapidly developing information technology.Therefore,with the advent of the information age,network trade has had a series of impacts on China’s economy,which has given wings to the take-off of China’s economy,but also made the development of China’s economy face a new environment and new challenges.Based on this,this paper first analyzes the connotation of network trade,and analyzes the impact of the network trade era on China’s economy.Through such a study,it aims to make China better seize the opportunities of the times and meet the challenges of the times in the process of promoting social and economic development,so as to achieve a good and rapid development of the national economy.展开更多
The risk points in the credit guarantee network of steel trade enterprises were identified by using the network analysis method in this paper. Firstly, the formation and operation mechanism of steel trade credit guara...The risk points in the credit guarantee network of steel trade enterprises were identified by using the network analysis method in this paper. Firstly, the formation and operation mechanism of steel trade credit guarantee network was analyzed.Secondly,a guarantee network was established to analyze the related network structure indexes based on the mutual guarantee data of 83 enterprises in a steel trade market. These indexes included centrality,honest broker,and structural hole. The results suggest that network analysis method can be used to find out the risk points of the guarantee network. Additionally,some recommendations are brought forth to reduce or prevent future crises.展开更多
Arriving to the east African coast in the 16th century, Portuguese faced an important and well-structured commercial network dominated by Muslim merchants. Operating throughout the Indian Ocean and in articulation wit...Arriving to the east African coast in the 16th century, Portuguese faced an important and well-structured commercial network dominated by Muslim merchants. Operating throughout the Indian Ocean and in articulation with the inland African trade routes by way of the coastal settlements from Bazaruto up to the north of Mozambique, this network bustled luxury goods and basic goods benefiting either from a network of inter-personal relationships and kinship that supported the whole business, or from an ancestral knowledge on the techniques and particular procedures indispensable to navigating in the Indian Ocean. This trade made the prosperity of small southern ports, like Sofala or Mozambique long before the Portuguese arrival. However, this trade was so much dependent on the network＇s capacity of organisation and the supply demand relation of the goods involved, as well as on other factors such as the political stability of the African kingdoms, the environmental changes that shaped flows and trade routes or the actual knowledge of the region and of the different forms of organization of local communities. By focusing in the ports of Sofala and Mozambique and the information provided by the Portuguese documents we intend to analyse its evolution during the 16th century in order to understand its role in the Indian Ocean commercial network under Portuguese rule.展开更多
为提升能源利用率并减少系统碳排放,构建了一个包含碳捕集、电转气设备的综合能源系统(integrated energy system,IES),同时引入碳交易机制,并提出一种考虑热网损耗的IES两阶段优化方法。第一阶段,计及热网损耗,以热源供热量最小为目标...为提升能源利用率并减少系统碳排放,构建了一个包含碳捕集、电转气设备的综合能源系统(integrated energy system,IES),同时引入碳交易机制,并提出一种考虑热网损耗的IES两阶段优化方法。第一阶段,计及热网损耗,以热源供热量最小为目标,优化热力管网流量及供回水温度;第二阶段,基于第一阶段优化后的热源供热量,在满足各约束条件的前提下,以系统运行成本、碳交易成本最低为目标,优化各机组出力。最后,对6节点电网、4节点气网、6节点热网模型的综合能源系统进行仿真。与对比方案相比,所提方案的日运行总成本降低15.5%,排碳量减少39.5%,验证了所提模型及策略的有效性。展开更多
基金CAS Priority Research Program,No.XDA20010102National Social Science Foundation of China,No.17VDL008
文摘Unimpeded trade is one of the cooperation priorities in the Belt and Road Initiative proposed by China. On 15 May 2017, the Joint Communique of the Leaders Roundtable of the Belt and Road Forum for International Cooperation reaffirmed the participants＇ shared commitment to build an open economy and ensure free and inclusive trade. The Belt and Road Initiative （BRI） is not only China＇s new action to drive its open and global develoPment, but also a platform for an increasing number of countries to explore free and inclusive trade and promote a universal, rule-based, open, non-discriminatory, and equitable multilateral trade system. It is therefore important to examine BRI and global trade networks. More specifically, the topological relationship between the this article first analyzes the community structure of trade networks using a community detection algorithm, and then estimates the topological relationship between different trade communities. The findings of this article are as follows. First, this research identified three trade communities and two sub-communities in the BRI trade network, in which China is the core, Russia is the sub-core of the biggest trade community, and India, United Arab Emirates, and Saudi Arabia are cores of the second trade community （South Asia-West Asia）. Second, it identified five trade communities in the global trade network, centred on China, USA, Russia, India-United Arab Emirates, and Ger- many-Netherlands-France-Britain and other European developed countries. Third, the topo- logical analysis indicated that in the global trade network, most BRI countries are attracted by the core nodes of the BRI regions, such as the China, Russia and India-United Arab Emirates core nodes, and have strong trade contacts with BRI countries. Most Central-East European countries are mainly attracted by Germany-Netherlands-France-Britain and other developed European countries with a low penetration of BRI trade. Although some Southeast Asian countries are incorporated into the Asia-Australia-South Africa community with China as the core, they still need to strengthen trade linkages with BRI countries.
基金supported by the Ministry of Education of the People’s Republic of China Humanities and Social Sciences Youth Foundation(Grant No.22YJC910014)the Social Sciences Planning Youth Project of Anhui Province(Grant No.AHSKQ2022D138)the Innovation Development Research Project of Anhui Province(Grant No.2021CX053).
文摘As a global strategic reserve resource,rare earth has been widely used in important industries,such as military equipment and biomedicine.However,existing analyses based solely on the total volume of rare earth trade fail to uncover the underlying competition and dependency dynamics.To address this gap,this paper employs the principles of trade preference and import similarity to construct dependency and competition networks.Complex network analysis is then employed to study the evolution of the global rare earth trade network from 2002 to 2018.The main conclusions are as follows.The global rare earth trade follows the Pareto principle,and the trade network shows a scale-free distribution.China has emerged as the world’s largest importer and exporter of rare earth since 2017.In the dependency network,China has become the most dependent country since 2006.The result of community division shows that China has separated from the American community and formed new communities with the Association of Southeast Asian Nations(ASEAN)countries.The United States of America has formed a super-strong community with European and Asian countries.In the competition network,the distribution of competition intensity follows a scale-free distribution.Most countries face low-intensity competition,but there are numerous competing countries.The competition related to China has increased significantly.Lastly,the competition source for the United States of America has shifted from Mexico to China,resulting in China,the USA,and Japan becoming the core participants in the competition network.
基金financially supported by the MOE (Ministry of Education in China) Project of Humanities and Social Sciences, China (20YJCZH057)the Hubei Province Social Science Fund General Project, China (2021147)the Xiangyang City Science and Technology Planning Project, Hubei Province, China (2021rkx04)
文摘The production and trade of primary products had a growing impact on the economic security of all countries and regions,and the strategic position of these products in the global trade network was becoming increasingly prominent.Based on complex network theory,this paper explored the spatial pattern and complex structural evolution of the global primary product trade network(GPPTN)during 1985-2015 by using index methods,such as centrality,Sankey diagram,and structure entropy,focusing on the diversified spatial structure of China’s import and export markets for primary products(with exceptions of Taiwan of China,Hong Kong of China,and Macao of China due to a lack of data)and their geographical implications for China’s energy security.The research offered the following key findings.The GPPTN showed an obvious spatial heterogeneity pattern,and the area of import consumption was more concentrated;however,the overall trend was decentralized.The trade center of gravity shifted eastwards and reflected the rise of emerging markets.The overall flow of the GPPTN was from west to east and from south to north.In terms of the community detection of the GPPTN,North America,Europe,and Asia increasingly presented an unbalanced“tripartite confrontation”.China’s exports of primary products were mainly concentrated in the Association of Southeast Asian Nations(ASEAN)and other peripheral regions of Asia,and its imports undergone a major transformation,gradually expanding from the peripheral regions of Asia to Africa,the Middle East,Latin America,and other parts of the world.Energy fuels also became the largest imported primary products.Based on the changing trend of structural entropy and main market share,the analysis showed that the stable supply of China’s energy diversification was gradually realized.In particular,the cooperation dividend proposed by the Belt and Road initiative became an important turning point and a strong support for the expansion of China’s energy market diversification pattern and guarantee of energy security.
基金supported by the National Natural Science Foundation of China(42471309)the National Key Research and Development Program of China(2020YFA0608504).
文摘The economic potential induced by environmental changes in the Arctic region garnered substantial interest,which positions Arctic trade as a crucial indicator in forecasting the impacts of climate change on the global economy.Nevertheless,attention devoted to the evolving dynamics of trade in the Arctic region remains scarce.In this study,we constructed export trade network in the Arctic region(including Denmark,Finland,Sweden,Norway,Iceland,the Canadian Arctic,the Russian Arctic,Alaska State of the USA,and Greenland)from 1990 to 2019 and analyzed its topology and evolutionary characteristics through complex network theory.We used a structural entropy index based on the distribution of the number of trading partners and the degree of trade concentration to assess export diversity,while we also utilized a revealed comparative advantage index to evaluate product export competitiveness using the share of trade volume of each type of product.The results indicate that the total export trade in the Arctic region increased by 53.4%during 1990-2019,with the most significant growth observed in the exports of chemical products and mineral fuels.The increasing complexity of trade network in the Arctic region resulted in the region’s export destinations no longer being concentrated on a few major countries and regions.The proportion of exports from the Arctic region to Europe decreased by 13.5%,while the proportion of exports from the Arctic region to Asia and North America increased by 6.8%and 3.1%,respectively.The Arctic region exhibited clear distinctions in the range of flows of different products,and its export trade was becoming increasingly diversified.Although differences in comparative advantages between products within individual countries or regions have narrowed,substantial gaps persist.The findings of this study can enhance the comprehensive understanding of the significance and function of Arctic trade activities within the global economy,providing a scientific basis for addressing the associated challenges and opportunities in the context of climate change.
基金2021 Graduate Innovation Special Fund Project"Study on Impacts of China's Grain Seed Trade Risk on Grain Supply Security Level"Management Science Project of Jiangxi Province"Study on Measures for Accelerating the Development of Agricultural High-tech Industries in Jiangxi Province".
文摘"Ensuring stability in foreign trade"and"ensuring food security"are essential parts of China's"six priorities"and"stability in six areas".Based on the data of bilateral food trade between countries during 1996-2018,using descriptive statistical analysis and social network analysis methods,this paper analyzed the changes of China's trade position in the world food trade network.It reached the following results.(i)China's position in the trade network has undergone a phased process of"remarkable improvement-continuous fluctuation-significant decline-steady growth".(ii)Export participation is better than import participation,the gap between trade export strength and import strength is widening,and the effective scale and constraint index gradually improve.(iii)The change of China's position in the food trade network is affected by geographical,economic,institutional and cultural factors.In view of these findings,it is recommended to improve node centrality,enhance network participation,improve network interconnection,and prevent international market risks,so as to better deal with the complex international environment.
文摘Both farmers and traders benefit from trade networking, which is crucial for the local economy. Therefore, it is crucial to understand how these networks operate, and how they can be managed more effectively. Throughout this study, we examine the economic networks formed between farmers and traders through the trade of food products. These networks are analyzed from the perspective of their structure and the factors that influence their development. Using data from 18 farmers and 15 traders, we applied exponential random graph models. The results of our study showed that connectivity, Popularity Spread, activity spread, good transportation systems, and high yields all affected the development of networks. Therefore, farmers’ productivity and high market demand can contribute to local food-crop trade. The network was not affected by reciprocity, open markets, proximity to locations, or trade experience of actors. Policy makers should consider these five factors when formulating policies for local food-crop trade. Additionally, local actors should be encouraged to use these factors to improve their network development. However, it is important to note that these factors alone cannot guarantee success. Policy makers and actors must also consider other factors such as legal frameworks, economic policies, and resource availability. Our approach can be used in future research to determine how traders and farmers can enhance productivity and profit in West Africa. This study addresses a research gap by examining factors influencing local food trade in a developing country.
文摘[Purpose]Global economic integration has intensified cereal trade,reshaping China’s grain security.Strengthening China’s role in the global cereal trade network is vital for improving trade patterns and safeguarding food security.[Design]Using bilateral trade data for eight major cereals in over 200 countries(1990–2021),this study applies social network analysis to construct global trade networks,measure key indicators,and visualize structural changes with Gephi.[Findings]From 1990 to 2021,average node degrees rose,with North America,Europe,and Australia as core hubs.Node degrees follow a power-law distribution,network density increased,clustering coefficients remained stable,and path lengths showed an inverted“U”trend.The network is moving toward decentralization and diversification.[Originality]By combining micro-level cereal trade analysis with social network methods,this study depicts the evolution of global trade structures,tracks China’s shifting position,and suggests new directions for national food security.
基金supported by the National Natural Science Foundation of China under Grant No. 70371070 Shanghai Leading Academic Discipline Project under Grant No. S30504Key Project for Fundamental Research of STCSM under Grant No. 06JC14057
文摘ymmetry of the world trade network provides a novel perspective to understand the world-wide trading system. However, symmetry in the world trade network （WTN） has been rarely studied so far. In this paper, the authors systematically explore the symmetry in WTN. The authors construct WTN in 2005 and explore the size and structure of its automorphism group, through which the authors find that WTN is symmetric, particularly, locally symmetric to a certain degree. Furthermore, the authors work out the symmetric motifs of WTN and investigate the structure and function of the symmetric motifs, coming to the conclusion that local symmetry will have great effect on the stability of the WTN and that continuous symmetry-breakings will generate complexity and diversity of the trade network. Finally, utilizing the local symmetry of the network, the authors work out the quotient of WTN, which is the structural skeleton dominating stability and evolution of WTN.
基金the National Natural Science Foundation of China(72171083)the Shanghai Outstanding Academic Leaders Plan,and the Fundamental Research Funds for the Central Universities.
文摘Pesticides are agricultural inputs that can significantly reduce yield losses,regulate plant growth,effectively liberate agricultural productivity,and improve food security.The availability of pesticides in economies worldwide is ensured by redistribution through international trade,with different economies playing different roles in this process.In this study,we measured and ranked the importance of economies using nine node metrics.We found that the clustering coefficient was negatively correlated with the other eight node metrics,whereas the other eight node metrics were positively correlated with each other and could be grouped into three communities(betweenness;in-degree,PageRank,authority,and in-closeness;out-degree,hub,and out-closeness).We further investigated the structural robustness of international pesticide trade networks proxied by large component size under three types of shocks to economies(node removal in descending,random,and ascending orders).The results showed that,except for the clustering coefficient,international pesticide trade networks are relatively robust under shocks to economies in ascending order but fragile under shocks to economies in descending order.By contrast,removing nodes with a clustering coefficient in ascending and descending order yielded similar robustness curves.Moreover,the structural robustness related to large component size evolved over time and exhibited an inverse U-shaped pattern.
文摘As the main food source for humans, the global movement of the three major grains significantly impacts human survival and development. To investigate the evolution of the world cereal trade network and its development trend, a weighted directed dynamic multiplexed network was established using historical data on cereal trade, cereal import dependency ratio, and arable land per capita. Inspired by the MLP framework, we redefined the weight determination method for computing layer weights and edge weights of the target layer, modified the CN, RA, AA, and PA indicators, and proposed the node similarity indicator for weighted directed networks. The AUC metric, which measures the accuracy of the algorithm, has also been improved in order to finally obtain the link prediction results for the grain trading network. The prediction results were processed, such as web-based presentation and community partition. It was found that the number of generalized trade agreements does not have a decisive impact on inter-country cereal trade. The former large grain exporters continue to play an important role in this trade network. In the future, the world trade in cereals will develop in the direction of more frequent intercontinental trade and gradually weaken the intracontinental cereal trade.
文摘With the rapid development of the Internet and information technology,network trade has emerged and broken through the traditional trade boundaries in the rapidly developing information technology.Therefore,with the advent of the information age,network trade has had a series of impacts on China’s economy,which has given wings to the take-off of China’s economy,but also made the development of China’s economy face a new environment and new challenges.Based on this,this paper first analyzes the connotation of network trade,and analyzes the impact of the network trade era on China’s economy.Through such a study,it aims to make China better seize the opportunities of the times and meet the challenges of the times in the process of promoting social and economic development,so as to achieve a good and rapid development of the national economy.
基金Social Science Programs Foundation of Ministry of Education of China(No.10YJA910002)
文摘The risk points in the credit guarantee network of steel trade enterprises were identified by using the network analysis method in this paper. Firstly, the formation and operation mechanism of steel trade credit guarantee network was analyzed.Secondly,a guarantee network was established to analyze the related network structure indexes based on the mutual guarantee data of 83 enterprises in a steel trade market. These indexes included centrality,honest broker,and structural hole. The results suggest that network analysis method can be used to find out the risk points of the guarantee network. Additionally,some recommendations are brought forth to reduce or prevent future crises.
文摘Arriving to the east African coast in the 16th century, Portuguese faced an important and well-structured commercial network dominated by Muslim merchants. Operating throughout the Indian Ocean and in articulation with the inland African trade routes by way of the coastal settlements from Bazaruto up to the north of Mozambique, this network bustled luxury goods and basic goods benefiting either from a network of inter-personal relationships and kinship that supported the whole business, or from an ancestral knowledge on the techniques and particular procedures indispensable to navigating in the Indian Ocean. This trade made the prosperity of small southern ports, like Sofala or Mozambique long before the Portuguese arrival. However, this trade was so much dependent on the network＇s capacity of organisation and the supply demand relation of the goods involved, as well as on other factors such as the political stability of the African kingdoms, the environmental changes that shaped flows and trade routes or the actual knowledge of the region and of the different forms of organization of local communities. By focusing in the ports of Sofala and Mozambique and the information provided by the Portuguese documents we intend to analyse its evolution during the 16th century in order to understand its role in the Indian Ocean commercial network under Portuguese rule.
文摘为提升能源利用率并减少系统碳排放,构建了一个包含碳捕集、电转气设备的综合能源系统(integrated energy system,IES),同时引入碳交易机制,并提出一种考虑热网损耗的IES两阶段优化方法。第一阶段,计及热网损耗,以热源供热量最小为目标,优化热力管网流量及供回水温度;第二阶段,基于第一阶段优化后的热源供热量,在满足各约束条件的前提下,以系统运行成本、碳交易成本最低为目标,优化各机组出力。最后,对6节点电网、4节点气网、6节点热网模型的综合能源系统进行仿真。与对比方案相比,所提方案的日运行总成本降低15.5%,排碳量减少39.5%,验证了所提模型及策略的有效性。
