Automatic Dependent Surveillance-Broadcast(ADS-B)technology,with its open signal sharing,faces substantial security risks from false signals and spoofing attacks when broadcasting Unmanned Aerial Vehicle(UAV)informati...Automatic Dependent Surveillance-Broadcast(ADS-B)technology,with its open signal sharing,faces substantial security risks from false signals and spoofing attacks when broadcasting Unmanned Aerial Vehicle(UAV)information.This paper proposes a security position verification technique based on Multilateration(MLAT)to detect false signals,ensuring UAV safety and reliable airspace operations.First,the proposed method estimates the current position of the UAV by calculating the Time Difference of Arrival(TDOA),Time Sum of Arrival(TSOA),and Angle of Arrival(AOA)information.Then,this estimated position is compared with the ADS-B message to eliminate false UAV signals.Furthermore,a localization model based on TDOA/TSOA/AOA is established by utilizing reliable reference sources for base station time synchronization.Additionally,an improved Chan-Taylor algorithm is developed,incorporating the Constrained Weighted Least Squares(CWLS)method to initialize UAV position calculations.Finally,a false signal detection method is proposed to distinguish between true and false positioning targets.Numerical simulation results indicate that,at a positioning error threshold of 150 m,the improved Chan-Taylor algorithm based on TDOA/TSOA/AOA achieves 100%accuracy coverage,significantly enhancing localization precision.And the proposed false signal detection method achieves a detection accuracy rate of at least 90%within a 50-meter error range.展开更多
Both the EU and China remain committed to safeguarding the multilateral trading system,which is in alignment with the bilateral and common interests of the world.
On March 24,the international symposium themed“Strengthen the Role of the United Nations and Promote Multilateralism”was held in Beijing.The event was hosted by the Ministry of Foreign Affairs of China,and supported...On March 24,the international symposium themed“Strengthen the Role of the United Nations and Promote Multilateralism”was held in Beijing.The event was hosted by the Ministry of Foreign Affairs of China,and supported by China Institute of International Studies(CIIS),the United Nations Association of China.展开更多
The global trade governance system is the institutional safeguard for maintaining the operation of world trade. It consists of governance entities, platforms and rules. Since the end of World War Ⅱ, the global trade ...The global trade governance system is the institutional safeguard for maintaining the operation of world trade. It consists of governance entities, platforms and rules. Since the end of World War Ⅱ, the global trade governance system has mainly referred to the multilateral trading system, with the General Agreement on Tariffs and Trade(GATT) and the World Trade Organization(WTO) serving as governance platforms.展开更多
In an era marked by rising protectionism and geopolitical tensions,the world faces a stark choice:embrace multilateral cooperation or succumb to unilateral hegemony.The United States’punitive tariff policies have exp...In an era marked by rising protectionism and geopolitical tensions,the world faces a stark choice:embrace multilateral cooperation or succumb to unilateral hegemony.The United States’punitive tariff policies have exposed the negative effect of economic coercion and isolation.Meanwhile,China’s commitment to openness,innovation,and shared prosperity offers a contrast,a testament to the enduring vitality of multilateralism and global integration.展开更多
AT a critical juncture in global climate governance,where pressures on multilateral cooperation are mounting,collaboration between China and the European Union(EU),rooted in their shared pursuit of pragmatism and tang...AT a critical juncture in global climate governance,where pressures on multilateral cooperation are mounting,collaboration between China and the European Union(EU),rooted in their shared pursuit of pragmatism and tangible outcomes,has demonstrated unique resilience and value.展开更多
Today,the world is undergoing profound changes unseen in a century,and a host of global challenges continue to emerge.The international community urgently requires effective global governance.As Chinese President Xi J...Today,the world is undergoing profound changes unseen in a century,and a host of global challenges continue to emerge.The international community urgently requires effective global governance.As Chinese President Xi Jinping has pointed out,multilateralism is the inevitable choice for addressing the world’s difficulties and challenges.1 However,various negative trends in international politics are undermining or impeding the effectiveness of multilateralism and aggravating the global governance deficit.Against this backdrop,it is essential to reassess the importance of multilateralism in global governance,identify the challenges it faces,and explore feasible pathways for collective action to advance global governance.展开更多
Safeguarding the resilience and stability of global industrial and supply chains provides a crucial guarantee for world economic development.Moreover,it aligns with the common interests of all countries.At its third p...Safeguarding the resilience and stability of global industrial and supply chains provides a crucial guarantee for world economic development.Moreover,it aligns with the common interests of all countries.At its third plenary session,the 20th Central Commit tee of the Communist Par ty of China(CPC)stressed that it would“facilitate international cooperation in industrial and supply chains”.China is firmly committed to supporting and enhancing the multilateral trading system centered on the World Trade Organization(WTO)in order to ensure the smooth and stable operation of these chains.展开更多
This year marks the 50th anniversary of the establishment of diplomatic relations between China and the EU.Over half a century,China and the EU have steadily enhanced political mutual trust,deepened mutually beneficia...This year marks the 50th anniversary of the establishment of diplomatic relations between China and the EU.Over half a century,China and the EU have steadily enhanced political mutual trust,deepened mutually beneficial cooperation,and firmly upheld multilateralism,bringing tangible benefits to both peoples and making a significant contribution to global peace and development.展开更多
After the 2008 global financial crisis, the global governance architecture underwent significant changes, accompanied by transformations in political, economic, diplomatic, and social spheres. What we had learnt since...After the 2008 global financial crisis, the global governance architecture underwent significant changes, accompanied by transformations in political, economic, diplomatic, and social spheres. What we had learnt since the end of World War Ⅱ was unable to make sense of the evolution and direction of this architecture.展开更多
China-Africa cooperation sets a benchmark for equitable development in a multipolar world Despite rising unilateralism and protectionism in the West and increasing uncertainties in global trade,China-Africa economic a...China-Africa cooperation sets a benchmark for equitable development in a multipolar world Despite rising unilateralism and protectionism in the West and increasing uncertainties in global trade,China-Africa economic and trade cooperation remains on a fast track,backed by concrete actions towards common modernisation.This collaboration reinforces solidarity across the Global South and contributes to greater stability and confidence in the global multilateral trading system.展开更多
On June 18, 2025, the second ChinaCentral Asia Summit was held in Astana, Kazakhstan. The member states of the China-Central Asia mechanism emphasized the importance of further deepening multilateral cooperation based...On June 18, 2025, the second ChinaCentral Asia Summit was held in Astana, Kazakhstan. The member states of the China-Central Asia mechanism emphasized the importance of further deepening multilateral cooperation based on principles of equality, mutual respect, and mutual benefit. They declared their commitment to continue strengthening friendly relations, deepening political trust, and expanding economic cooperation among the six nations.展开更多
The U.S.administration's decision tounilaterally impose sweeping tariff increas-es on tmported goods represents a signifi-cant challenge to the existing global tradingsystem,which has long been structuredaround mu...The U.S.administration's decision tounilaterally impose sweeping tariff increas-es on tmported goods represents a signifi-cant challenge to the existing global tradingsystem,which has long been structuredaround multilateral(WTO),regional,andbilateral(FTA)trade agreements.展开更多
With the profound changes taking place in the international power structure and the accelerated changes occurring in the world that have not been seen in a century,the discord between China and the United States(US)in...With the profound changes taking place in the international power structure and the accelerated changes occurring in the world that have not been seen in a century,the discord between China and the United States(US)in the realm of global governance is becoming increasingly prominent.Moreover,the raging COVID-19 pandemic has aggravated the divergences between the two countries in terms of global governance strategy.Since the end of World War II,although the diplomatic strategies of the US and their implementation have varied from administration to administration,such strategies have generally been defined by the US desire for hegemony in global governance.China’s engagement in global governance,by contrast,has undergone twists and turns,and its strategies and policies have kept pace with the times,which has gradually led to a global governance strategy that highlights extensive consultation,joint contribution,and shared benefits.The divergences between China and the US in terms of global governance strategy are embodied in governance values,areas,and approaches,relations among governance entities,and balance between national and global governance,which have resulted mainly from the two countries’different cultural backgrounds,historical traditions,realistic goals,and national strength.In the context of intensifying competition among major countries today,these strategic divergences between China and the US have exerted a profound impact on global governance cooperation and the reform of the global governance system,and exacerbated the fragmentation of global governance and the competition over leadership.Therefore,a comparison of the global governance strategies pursued by China and the US will help enhance mutual understanding,avoid confrontation and conflict,properly manage disagreements,and promote a healthy and stable development of bilateral relations between China and the US.展开更多
Coalbed methane(CBM)drilling and completion technologies(DCTs)are signifcant basis for achieving efcient CBM exploration and exploitation.Characteristics of CBM reservoirs vary in diferent regions around the world,the...Coalbed methane(CBM)drilling and completion technologies(DCTs)are signifcant basis for achieving efcient CBM exploration and exploitation.Characteristics of CBM reservoirs vary in diferent regions around the world,thereby,it is crucial to develop,select and apply the optimum DCTs for each diferent CBM reservoir.This paper frstly reviews the development history of CBM DCTs throughout worldwide and clarifes its overall development tendency.Secondly,diferent well types and its characteristics of CBM exploitation are summarized,and main application scopes of these well types are also discussed.Then,the key technologies of CBM drilling(directional drilling tools,measurement while drilling,geo-steering drilling,magnetic guidance drilling,underbalanced drilling and drilling fuids),and the key technologies of CBM completion(open-hole,cavity and under-ream completion,cased-hole completion,screen pipe completion and horizontal well completion)are summarized and analyzed,it is found that safe,economic and efcient development of CBM is inseparable from the support of advanced technologies.Finally,based on the current status of CBM development,the achievements,existing challenges and future prospects are summarized and discussed from the perspective of CBM DCTs.展开更多
By using mathematical reasoning, this paper demonstrates the mathematical intervening principle: “Virtual disease is to fill his mother but real disease is to rush down his son” (虚则补其母, 实则泄其子) and “Strong...By using mathematical reasoning, this paper demonstrates the mathematical intervening principle: “Virtual disease is to fill his mother but real disease is to rush down his son” (虚则补其母, 实则泄其子) and “Strong inhibition of the same time, support the weak” (抑强扶弱) based on “Yin Yang Wu Xing” Theory in image mathematics of Traditional Chinese Mathematics (TCMath). We defined generalized relations and generalized reasoning, introduced the concept of steady multilateral systems with two non-compatibility relations, and discussed its energy properties. Later based on the intervention principle in image mathematics of TCMath and treated the research object of the image mathematics as a steady multilateral system, it has been proved that the mathematical intervening principle is true. The kernel of this paper is the existence and reasoning of the non-compatibility relations in steady multilateral systems, and it accords with the oriental thinking model.展开更多
Currently, cybersecurity and cyber resilience are emerging and urgent issues in nextgeneration air traffic surveillance systems, which depend primarily on Automatic Dependent Surveillance-Broadcast(ADS-B) owing to its...Currently, cybersecurity and cyber resilience are emerging and urgent issues in nextgeneration air traffic surveillance systems, which depend primarily on Automatic Dependent Surveillance-Broadcast(ADS-B) owing to its low cost and high accuracy. Unfortunately, ADS-B is prone to cyber-attacks. To verify the ADS-B positioning data of aircraft, multilateration(MLAT)techniques that use Time Differences of Arrivals(TDoAs) have been proposed. MLAT exhibits low accuracy in determining aircraft positions. Recently, a novel technique using a theoretically calculated TDoA fingerprint map has been proposed. This technique is less dependent on the geometry of sensor deployment and achieves better accuracy than MLAT. However, the accuracy of the existing technique is not sufficiently precise for determining aircraft positions and requires a long computation time. In contrast, this paper presents a reliable surveillance framework using an Actual TDoA-Based Augmentation System(ATBAS). It uses historically recorded real-data from the OpenSky network to train our TDoA fingerprint grid network. Our results show that the accuracy of the proposed ATBAS framework in determining the aircraft positions is significantly better than those of the MLAT and expected TDoA techniques by 56.93% and 48.86%, respectively. Additionally, the proposed framework reduced the computation time by 77% compared with the expected TDoA technique.展开更多
By using mathematical reasoning, this paper demonstrates the treatment principle: “Virtual disease is to fill his mother but real disease is to rush down his son” and “Strong inhibition of the same time, support th...By using mathematical reasoning, this paper demonstrates the treatment principle: “Virtual disease is to fill his mother but real disease is to rush down his son” and “Strong inhibition of the same time, support the weak” based on “Yin Yang Wu Xing” Theory in Traditional Chinese Medicine (TCM). We defined two kinds of opposite relations and one kind of equivalence relation, introduced the concept of steady multilateral systems with two non-compatibility relations, and discussed its energy properties. Later based on the treatment of TCM and treated the healthy body as a steady multilateral system, it has been proved that the treatment principle is true. The kernel of this paper is the existence and reasoning of the non-compatibility relations in steady multilateral systems, and it accords with the oriental thinking model.展开更多
基金supported by the National Natural Science Foundation of China(Nos.U2441250,62301380,and 62231027)Natural Science Basic Research Program of Shaanxi,China(2024JC-JCQN-63)+3 种基金the Key Research and Development Program of Shaanxi,China(No.2023-YBGY-249)the Guangxi Key Research and Development Program,China(No.2022AB46002)the China Postdoctoral Science Foundation(No.2022M722504 and 2024T170696)the Innovation Capability Support Program of Shaanxi,China(No.2024RS-CXTD-01).
文摘Automatic Dependent Surveillance-Broadcast(ADS-B)technology,with its open signal sharing,faces substantial security risks from false signals and spoofing attacks when broadcasting Unmanned Aerial Vehicle(UAV)information.This paper proposes a security position verification technique based on Multilateration(MLAT)to detect false signals,ensuring UAV safety and reliable airspace operations.First,the proposed method estimates the current position of the UAV by calculating the Time Difference of Arrival(TDOA),Time Sum of Arrival(TSOA),and Angle of Arrival(AOA)information.Then,this estimated position is compared with the ADS-B message to eliminate false UAV signals.Furthermore,a localization model based on TDOA/TSOA/AOA is established by utilizing reliable reference sources for base station time synchronization.Additionally,an improved Chan-Taylor algorithm is developed,incorporating the Constrained Weighted Least Squares(CWLS)method to initialize UAV position calculations.Finally,a false signal detection method is proposed to distinguish between true and false positioning targets.Numerical simulation results indicate that,at a positioning error threshold of 150 m,the improved Chan-Taylor algorithm based on TDOA/TSOA/AOA achieves 100%accuracy coverage,significantly enhancing localization precision.And the proposed false signal detection method achieves a detection accuracy rate of at least 90%within a 50-meter error range.
文摘Both the EU and China remain committed to safeguarding the multilateral trading system,which is in alignment with the bilateral and common interests of the world.
文摘On March 24,the international symposium themed“Strengthen the Role of the United Nations and Promote Multilateralism”was held in Beijing.The event was hosted by the Ministry of Foreign Affairs of China,and supported by China Institute of International Studies(CIIS),the United Nations Association of China.
文摘The global trade governance system is the institutional safeguard for maintaining the operation of world trade. It consists of governance entities, platforms and rules. Since the end of World War Ⅱ, the global trade governance system has mainly referred to the multilateral trading system, with the General Agreement on Tariffs and Trade(GATT) and the World Trade Organization(WTO) serving as governance platforms.
文摘In an era marked by rising protectionism and geopolitical tensions,the world faces a stark choice:embrace multilateral cooperation or succumb to unilateral hegemony.The United States’punitive tariff policies have exposed the negative effect of economic coercion and isolation.Meanwhile,China’s commitment to openness,innovation,and shared prosperity offers a contrast,a testament to the enduring vitality of multilateralism and global integration.
文摘AT a critical juncture in global climate governance,where pressures on multilateral cooperation are mounting,collaboration between China and the European Union(EU),rooted in their shared pursuit of pragmatism and tangible outcomes,has demonstrated unique resilience and value.
文摘Today,the world is undergoing profound changes unseen in a century,and a host of global challenges continue to emerge.The international community urgently requires effective global governance.As Chinese President Xi Jinping has pointed out,multilateralism is the inevitable choice for addressing the world’s difficulties and challenges.1 However,various negative trends in international politics are undermining or impeding the effectiveness of multilateralism and aggravating the global governance deficit.Against this backdrop,it is essential to reassess the importance of multilateralism in global governance,identify the challenges it faces,and explore feasible pathways for collective action to advance global governance.
文摘Safeguarding the resilience and stability of global industrial and supply chains provides a crucial guarantee for world economic development.Moreover,it aligns with the common interests of all countries.At its third plenary session,the 20th Central Commit tee of the Communist Par ty of China(CPC)stressed that it would“facilitate international cooperation in industrial and supply chains”.China is firmly committed to supporting and enhancing the multilateral trading system centered on the World Trade Organization(WTO)in order to ensure the smooth and stable operation of these chains.
文摘This year marks the 50th anniversary of the establishment of diplomatic relations between China and the EU.Over half a century,China and the EU have steadily enhanced political mutual trust,deepened mutually beneficial cooperation,and firmly upheld multilateralism,bringing tangible benefits to both peoples and making a significant contribution to global peace and development.
文摘After the 2008 global financial crisis, the global governance architecture underwent significant changes, accompanied by transformations in political, economic, diplomatic, and social spheres. What we had learnt since the end of World War Ⅱ was unable to make sense of the evolution and direction of this architecture.
文摘China-Africa cooperation sets a benchmark for equitable development in a multipolar world Despite rising unilateralism and protectionism in the West and increasing uncertainties in global trade,China-Africa economic and trade cooperation remains on a fast track,backed by concrete actions towards common modernisation.This collaboration reinforces solidarity across the Global South and contributes to greater stability and confidence in the global multilateral trading system.
文摘On June 18, 2025, the second ChinaCentral Asia Summit was held in Astana, Kazakhstan. The member states of the China-Central Asia mechanism emphasized the importance of further deepening multilateral cooperation based on principles of equality, mutual respect, and mutual benefit. They declared their commitment to continue strengthening friendly relations, deepening political trust, and expanding economic cooperation among the six nations.
文摘The U.S.administration's decision tounilaterally impose sweeping tariff increas-es on tmported goods represents a signifi-cant challenge to the existing global tradingsystem,which has long been structuredaround multilateral(WTO),regional,andbilateral(FTA)trade agreements.
基金the phased result of a school-level research project(2020)of the Party School of the Central Committee of CPC(National Academy of Governance)entitled“Research on the Concept of Global Governance Featuring Extensive Consultation,Joint Contribution,and Shared Benefits amid Great Changes of the World Unseen in a Century”(2020YB015)。
文摘With the profound changes taking place in the international power structure and the accelerated changes occurring in the world that have not been seen in a century,the discord between China and the United States(US)in the realm of global governance is becoming increasingly prominent.Moreover,the raging COVID-19 pandemic has aggravated the divergences between the two countries in terms of global governance strategy.Since the end of World War II,although the diplomatic strategies of the US and their implementation have varied from administration to administration,such strategies have generally been defined by the US desire for hegemony in global governance.China’s engagement in global governance,by contrast,has undergone twists and turns,and its strategies and policies have kept pace with the times,which has gradually led to a global governance strategy that highlights extensive consultation,joint contribution,and shared benefits.The divergences between China and the US in terms of global governance strategy are embodied in governance values,areas,and approaches,relations among governance entities,and balance between national and global governance,which have resulted mainly from the two countries’different cultural backgrounds,historical traditions,realistic goals,and national strength.In the context of intensifying competition among major countries today,these strategic divergences between China and the US have exerted a profound impact on global governance cooperation and the reform of the global governance system,and exacerbated the fragmentation of global governance and the competition over leadership.Therefore,a comparison of the global governance strategies pursued by China and the US will help enhance mutual understanding,avoid confrontation and conflict,properly manage disagreements,and promote a healthy and stable development of bilateral relations between China and the US.
基金supported by the Youth Scientific and Technological Innovation Team Foundation of Southwest Petroleum University(2019CXTD09)the Program of Introducing Talents of Discipline to Chinese Universities(111 Plan)(D18016).
文摘Coalbed methane(CBM)drilling and completion technologies(DCTs)are signifcant basis for achieving efcient CBM exploration and exploitation.Characteristics of CBM reservoirs vary in diferent regions around the world,thereby,it is crucial to develop,select and apply the optimum DCTs for each diferent CBM reservoir.This paper frstly reviews the development history of CBM DCTs throughout worldwide and clarifes its overall development tendency.Secondly,diferent well types and its characteristics of CBM exploitation are summarized,and main application scopes of these well types are also discussed.Then,the key technologies of CBM drilling(directional drilling tools,measurement while drilling,geo-steering drilling,magnetic guidance drilling,underbalanced drilling and drilling fuids),and the key technologies of CBM completion(open-hole,cavity and under-ream completion,cased-hole completion,screen pipe completion and horizontal well completion)are summarized and analyzed,it is found that safe,economic and efcient development of CBM is inseparable from the support of advanced technologies.Finally,based on the current status of CBM development,the achievements,existing challenges and future prospects are summarized and discussed from the perspective of CBM DCTs.
文摘By using mathematical reasoning, this paper demonstrates the mathematical intervening principle: “Virtual disease is to fill his mother but real disease is to rush down his son” (虚则补其母, 实则泄其子) and “Strong inhibition of the same time, support the weak” (抑强扶弱) based on “Yin Yang Wu Xing” Theory in image mathematics of Traditional Chinese Mathematics (TCMath). We defined generalized relations and generalized reasoning, introduced the concept of steady multilateral systems with two non-compatibility relations, and discussed its energy properties. Later based on the intervention principle in image mathematics of TCMath and treated the research object of the image mathematics as a steady multilateral system, it has been proved that the mathematical intervening principle is true. The kernel of this paper is the existence and reasoning of the non-compatibility relations in steady multilateral systems, and it accords with the oriental thinking model.
文摘Currently, cybersecurity and cyber resilience are emerging and urgent issues in nextgeneration air traffic surveillance systems, which depend primarily on Automatic Dependent Surveillance-Broadcast(ADS-B) owing to its low cost and high accuracy. Unfortunately, ADS-B is prone to cyber-attacks. To verify the ADS-B positioning data of aircraft, multilateration(MLAT)techniques that use Time Differences of Arrivals(TDoAs) have been proposed. MLAT exhibits low accuracy in determining aircraft positions. Recently, a novel technique using a theoretically calculated TDoA fingerprint map has been proposed. This technique is less dependent on the geometry of sensor deployment and achieves better accuracy than MLAT. However, the accuracy of the existing technique is not sufficiently precise for determining aircraft positions and requires a long computation time. In contrast, this paper presents a reliable surveillance framework using an Actual TDoA-Based Augmentation System(ATBAS). It uses historically recorded real-data from the OpenSky network to train our TDoA fingerprint grid network. Our results show that the accuracy of the proposed ATBAS framework in determining the aircraft positions is significantly better than those of the MLAT and expected TDoA techniques by 56.93% and 48.86%, respectively. Additionally, the proposed framework reduced the computation time by 77% compared with the expected TDoA technique.
文摘By using mathematical reasoning, this paper demonstrates the treatment principle: “Virtual disease is to fill his mother but real disease is to rush down his son” and “Strong inhibition of the same time, support the weak” based on “Yin Yang Wu Xing” Theory in Traditional Chinese Medicine (TCM). We defined two kinds of opposite relations and one kind of equivalence relation, introduced the concept of steady multilateral systems with two non-compatibility relations, and discussed its energy properties. Later based on the treatment of TCM and treated the healthy body as a steady multilateral system, it has been proved that the treatment principle is true. The kernel of this paper is the existence and reasoning of the non-compatibility relations in steady multilateral systems, and it accords with the oriental thinking model.
