Chile,a pioneer and benchmark partner for China's free trade.cooperation in Latin America,holds a special position in China-Latin America economic and trade relations.It was the first Latin American country to sig...Chile,a pioneer and benchmark partner for China's free trade.cooperation in Latin America,holds a special position in China-Latin America economic and trade relations.It was the first Latin American country to sign a bilateral free trade agreement with China and the first to reach an upgraded protocol.Chile also established mutual recognition of Authorized Economic Operators(AEO)with China,the first country in South America to do so.展开更多
Objective:To explore the clinical benefits achieved by implementing the operating room nursing cooperation path for patients undergoing laparoscopic hysterectomy.Methods:64 laparoscopic hysterectomy cases were divided...Objective:To explore the clinical benefits achieved by implementing the operating room nursing cooperation path for patients undergoing laparoscopic hysterectomy.Methods:64 laparoscopic hysterectomy cases were divided into groups according to the order of admission.The control group received routine perioperative care.The observation group implemented the nursing cooperation path in the operating room on the same basis as the control group.The two groups’physiological responses,stimulus indicators,anxiety,and complication rates were compared.Results:The heart rate,blood pressure 0.5 hours after surgery,anxiety scores 1 day before and 3 days after surgery,and the total number of complications in the observation group were all lower than those in the control group(P<0.05).Conclusion:The development of a nursing cooperation path in the operating room can help patients undergoing laparoscopic hysterectomy reduce heart rate,blood pressure,stress responses,and the risk of complications,and is worthy of promotion.展开更多
Cooperative guidance is a method for achieving combat objectives through information sharing and cooperative effects,and has emerged as a significant research area in the fields of missile guidance and systematic warf...Cooperative guidance is a method for achieving combat objectives through information sharing and cooperative effects,and has emerged as a significant research area in the fields of missile guidance and systematic warfare.This study presents a systematic review and analysis of current research on cooperative guidance.First,a bibliometric analysis is conducted on 513 articles using the Scopus database and CiteSpace software to assess keyword clustering,keyword cooccurrence,and keyword burst,and to later visualize the results.Second,fundamental theories of cooperative guidance,including relative motion modeling methods,algebraic graph theory,and multi-agent consensus theory,are summarized.Subsequently,an overview of current cooperative laws and corresponding analysis methods is provided,with categorization based on the cooperative structure and convergence performance.Finally,we summarize current research developments based on five perspectives and propose a developmental framework based on five layers(cyber,physical,decision,information,and system),discussing potential future advancements in cooperative terminal guidance.This framework emphasizes five key areas of research:networked,heterogeneous,integrated,intelligent,and group cooperations,with the goal of offering trends and insights for futurework.展开更多
Under the background of"Digital Commerce for Rural Vitalization",rural E-commerce has experienced rapid development.However,agricultural products like strawberries,often produced by small-scale,fragmented,an...Under the background of"Digital Commerce for Rural Vitalization",rural E-commerce has experienced rapid development.However,agricultural products like strawberries,often produced by small-scale,fragmented,and less competitive individual farmers,struggle to meet the compliance and scalability demands of E-commerce,thereby constraining high-quality local economic development.Aiming to address this issue,this paper,guided by relevant policies and strategies,employs case analysis and logical deduction to explore the industrialization path of the"Cooperative+E-commerce"model for the strawberry industry.The research finds that by optimizing the cooperative's organizational structure,implementing multi-channel E-commerce strategies,upgrading the supply chain(including cold chain and quality traceability),and engaging in collaborative brand building,a robust industrial system can be formed.Supplemented by benefit evaluation,policy support,and regulatory oversight,this system can effectively bridge small-scale production with the broader market.This study concludes that this pathway can enhance the added value of the strawberry industry,increase farmer incomes,and provide practical insights for promoting high-quality local economic development.展开更多
Virtual coupling is a novel technology that enables trains to run closely together without physical connections through communication and automation systems.The paper addresses an adaptive polynomial approximation alg...Virtual coupling is a novel technology that enables trains to run closely together without physical connections through communication and automation systems.The paper addresses an adaptive polynomial approximation algorithm for the cooperative control of high-speed trains(HSTs)under virtual coupling.It aims to solve the cooperative tracking control problem of HST formation operations under various scenarios,including known and unknown parameters.To enable the HST formation system to achieve cooperative operation while ensuring an appropriate spacing distance,the tracking errors of displacement and speed throughout the entire operation converge to zero.The proposed control strategy focuses on adopting polynomial approximation to handle unknown parameters,which are estimated via adaptive laws.Additionally,the unknown parameters of the HSTs are estimated online through adaptive laws.Experimental results verify the effectiveness of this method.展开更多
In this paper,a novel cooperative collision avoidance control strategy with relative velocity information for redundant robotic manipulators is derived to guarantee the behavioral safety of robots in the cooperative o...In this paper,a novel cooperative collision avoidance control strategy with relative velocity information for redundant robotic manipulators is derived to guarantee the behavioral safety of robots in the cooperative operational task.This strategy can generate the collision-free trajectory of the robotic links in real-time,which is to realize that the robot can avoid moving obstacles less conservatively and ensure tracking accuracy of terminal end-effector tasks in performing cooperative tasks.For the case where there is interference between the moving obstacle and the desired path of the robotic end-effector,the method inherits the null-space-based self-motion characteristics of the redundant manipulator,integrates the relative motion information,and uses the improved artificial potential field method to design the control items,which are used to generate the collision avoidance motion and carry out moving obstacles smoothly and less conservatively.At the same time,the strategy maintains the kinematic constraint relationship of dual-arm cooperatives,to meet the real-time collision avoidance task under collaborative tasks.Finally,the algorithm simulation indicates that the method can better ensure the tracking accuracy of the end-effector task and carry out moving obstacles smoothly.The experimental results show that the method can generate the real-time collision-free trajectory of the robot in the cooperative handling task,and the joint movement is continuous and stable.展开更多
We studied the effect of population density in a spatial public goods game.We found that the effect on the evolution of cooperation is very complex when the strategy learning and mobility of players in a long range ar...We studied the effect of population density in a spatial public goods game.We found that the effect on the evolution of cooperation is very complex when the strategy learning and mobility of players in a long range are considered in a two-dimensional lattice.As the learning range is larger than the mobility range,the system is driven to enter into a cooperation state for a low population density,because a small local group is beneficial to sustain a high level of cooperation.As population density increases to a moderate range,the mobility of players from a domain invaded by defectors supports the evolution stability of cooperation.When the mobility range is larger than the learning range,a formation of compact domains of cooperators promotes cooperation as the population density becomes high.展开更多
The domain of foreign economic and technological cooperation in Shandong Province covers a very wide range of items. Developing its export-oriented economy, the province will focus on actively expanding the use of for...The domain of foreign economic and technological cooperation in Shandong Province covers a very wide range of items. Developing its export-oriented economy, the province will focus on actively expanding the use of foreign funds to operate foreigninvested and overseas展开更多
China s cooperation with Brazil, one of the largest countries in the third world, in the areas of space technology development and application has a great significance in the world. A joint program for the development...China s cooperation with Brazil, one of the largest countries in the third world, in the areas of space technology development and application has a great significance in the world. A joint program for the development of earth resources satellites is briefly introduced in this article.展开更多
This paper reviews a local anesthesia for resection of back mass, and the rescue of patients with sudden apnea during the operation. It also summarizes the nursing experience and shortcomings of the visiting nurses du...This paper reviews a local anesthesia for resection of back mass, and the rescue of patients with sudden apnea during the operation. It also summarizes the nursing experience and shortcomings of the visiting nurses during the operation, which provides relevant experience for the future local anesthesia operation for patients with cardiovascular complications. The patient underwent left back mass resection under local anesthesia. Blood pressure, heart rate and blood oxygen saturation were monitored. The right lateral position was adopted during the operation. During the 5-minute operation to separate the tumor, the visiting nurse noticed that the patient was pale and weak in answering the questions, and immediately she cried out. The ECG monitor showed that the heart rate was 45 beats/min and the SpO2 was 85%, with continuous decrease. Immediately call the surgeon to stop the operation. Change the patient from lateral position to supine position. Due to the timely rescue and proper measures, the patients heart rate rose to 70 beats/min, BP120/70mmHg, R22 beats/min, SpO2 was 98% after about 10 minutes. The patient regained consciousness and was able to correctly answer the questions. After 15 minutes of observation, the patients condition was stable and there was no discomfort. The right lateral decubitus position was placed again and the operation was completed after the drape was disinfected again. Conclusion: local anesthesia operation has certain risks. Attention should be paid to local anesthesia operation for patients with cardiovascular and other complications. Preoperative preparation should be adequate, peripheral veins should be opened regularly, and ECG and blood pressure should be monitored. During the operation, the patients complexion, consciousness and breathing were closely observed. If there is any abnormal situation, the surgeon should be reported in time and the emergency plan should be started to ensure the safety of the patients during the operation and to improve the quality of nursing cooperation during the operation.展开更多
In order to improve network connectivity in clustered wireless sensor networks,a node cooperative algorithm based on virtual antenna arrays is proposed.All the nodes in the network are assumed to be clustered via Pois...In order to improve network connectivity in clustered wireless sensor networks,a node cooperative algorithm based on virtual antenna arrays is proposed.All the nodes in the network are assumed to be clustered via Poisson Voronoi tessellation（PVT）.The activation of the node cooperative algorithm is determined by the cluster heads（CHs） according to communication links.When the cooperative algorithm is activated,the CH selects cooperative nodes（CNs） from its members to form a virtual antenna array.With the cooperation,nodes can extend the inter-cluster communication range to directly contact with further nodes after a coverage hole is detected,or compensate for channel gains while inter-cluster transmission fails due to deep channel fading.Simulation results show that the proposed algorithm achieves better network connectivity and energy efficiency.It can reduce outage probability,sustain network connectivity and maintain operations as long as possible,which prolongs network operation time.展开更多
With the rapid development of Unmanned Aerial Vehicle(UAV)technology,one of the emerging fields is to utilize multi-UAV as a team under autonomous control in a complex environment.Among the challenges in fully achievi...With the rapid development of Unmanned Aerial Vehicle(UAV)technology,one of the emerging fields is to utilize multi-UAV as a team under autonomous control in a complex environment.Among the challenges in fully achieving autonomous control,Cooperative task assignment stands out as the key function.In this paper,we analyze the importance and difficulties of multiUAV cooperative task assignment in characterizing scenarios and obtaining high-quality solutions.Furthermore,we present three promising directions for future research:Cooperative task assignment in a dynamic complex environment,in an unmanned-manned aircraft system and in a UAV swarm.Our goal is to provide a brief review of multi-UAV cooperative task assignment for readers to further explore.展开更多
Taking three typical farmers' specialized cooperatives in Jingyuan County of Gansu Province as example,this paper compared with the operating mode of three cooperatives and their position in the agricultural indus...Taking three typical farmers' specialized cooperatives in Jingyuan County of Gansu Province as example,this paper compared with the operating mode of three cooperatives and their position in the agricultural industry chain,and analyzed operating characteristics,problems,and similarities of three cooperatives and their functions in the agricultural industry chain.The study indicated that the farmers' specialized cooperatives can accurately find their position in the agricultural industry chain.This is helpful for raising their comprehensive competitiveness and it is very important to manage the survival and development of farmers' specialized cooperatives,which is of utmost importance to their effective operation.According to this study,the government should strengthen its support,speed up the cultivation of new-type professional farmers,while farmers' specialized cooperatives should grasp the operating characteristics,locate themselves and integrate multi-resources.These are effective measures for promoting healthy operation of farmers' specialized cooperatives.展开更多
In relay-assisted cooperative communication,relay nodes help forwarding the information of a source node in case of link failure between the source and a destination.Although user cooperation improves the overall effi...In relay-assisted cooperative communication,relay nodes help forwarding the information of a source node in case of link failure between the source and a destination.Although user cooperation improves the overall efficiency of the network,it requires incentive to stimulate potential relay nodes to assist the source by forwarding its data to the destination.Moreover,the potential relays are better informed than the source about their channel conditions to destination,which results in asymmetric information between the source and the relays.In this paper,we study the problem of lack of forwarding incentive in cooperative communication when channel state information of relays is private information and not known by the source.To tackle this problem,we apply the principle of contract theory to a cooperative wireless system.Source first designs incentive compatible and individually rational contract,consisting of a set of power-credit pairs.Then it broadcasts contract items to nearby nodes.Once the source node receives reply messages from the volunteer relays,it chooses one or more relays based on its requirements and communication starts.Simulation results show how credit assignment works in order to stimulate relays to cooperate and prevents relays from cheating behavior.展开更多
Establishment of farmers' professional cooperatives is an effective approach of settling conflicts between small-scale production of rural households and great market, however, there are still many problems such a...Establishment of farmers' professional cooperatives is an effective approach of settling conflicts between small-scale production of rural households and great market, however, there are still many problems such as low level of standardization, unscientific market positioning, poor capacity of mitigating risks, and unfavorable ecological benefits. This study, based on field investigation data and successful support experience, further explored operation and management problems existing in Jilin Farming Cooperative, and proposed pertinent solutions so as to enhance the high-efficiency and standard operation of farmers' professional cooperatives in Jilin Province and even China.展开更多
In this paper, we consider cooperative hyperbolic systems involving Schr?dinger operator defined on ?Rn. First we prove the existence and uniqueness of the state for these systems. Then we find the necessary and suffi...In this paper, we consider cooperative hyperbolic systems involving Schr?dinger operator defined on ?Rn. First we prove the existence and uniqueness of the state for these systems. Then we find the necessary and sufficient conditions of optimal control for such systems of the boundary type. We also find the necessary and sufficient conditions of optimal control for same systems when the observation is on the boundary.展开更多
After six years of development,the number of farmer cooperatives in Yanbian area was increased from 72 in 2007 to 2600 in 2012.It has become an important part of local modern agricultural operation.Through the survey ...After six years of development,the number of farmer cooperatives in Yanbian area was increased from 72 in 2007 to 2600 in 2012.It has become an important part of local modern agricultural operation.Through the survey and research of current status of farmer cooperatives in Yanbian area,we analyze the deficiencies in capital,technology and human resources during the operating to thoroughly understand its operating status.On this basis,we put forth some recommendations for the development of farmer cooperatives in Yanbian area:implementing industrialization operation;developing long-term development strategy;seeking the support of research institutions and colleges;increasing the types of services;enhancing the value-added.展开更多
Control systems are being changed from wired to wireless communications because of flexibility, mobility and extensibility of wireless communication systems;however the reliability of wireless communications is suspec...Control systems are being changed from wired to wireless communications because of flexibility, mobility and extensibility of wireless communication systems;however the reliability of wireless communications is suspected. In this paper, we propose cooperative communication scheme for wireless control systems which consist of a controller and multiple machines;these machines cooperatively work in a group and for the same duty. In the proposed method, the controller can communicate with machines directly or via other machines, whereas in the conventional method, the controller only communicates with machines directly. The simple 2-link arm plant is used to evaluate our proposed system, and the simulation results indicate that the proposed method is more accurate, and more stable than the conventional method.展开更多
We conduct questionnaire survey of migrant workers in Wenjiang District and Jintang County of Chengdu City,respectively,using the method of key-point investigation and the sampling survey. We describe the status quo o...We conduct questionnaire survey of migrant workers in Wenjiang District and Jintang County of Chengdu City,respectively,using the method of key-point investigation and the sampling survey. We describe the status quo of the sample migrant workers' participation in the New Rural Cooperative Medical System,analyze the issues concerning migrant workers' participation in the New Rural Cooperative Medical System,and put forward the countermeasures and recommendations as follows: using many types of medical insurance; establishing universal reimbursement points in strange land and premium-paying system for migrant workers; making the proportion of reimbursement open and transparent; establishing and improving medicare security system for migrant workers.展开更多
文摘Chile,a pioneer and benchmark partner for China's free trade.cooperation in Latin America,holds a special position in China-Latin America economic and trade relations.It was the first Latin American country to sign a bilateral free trade agreement with China and the first to reach an upgraded protocol.Chile also established mutual recognition of Authorized Economic Operators(AEO)with China,the first country in South America to do so.
文摘Objective:To explore the clinical benefits achieved by implementing the operating room nursing cooperation path for patients undergoing laparoscopic hysterectomy.Methods:64 laparoscopic hysterectomy cases were divided into groups according to the order of admission.The control group received routine perioperative care.The observation group implemented the nursing cooperation path in the operating room on the same basis as the control group.The two groups’physiological responses,stimulus indicators,anxiety,and complication rates were compared.Results:The heart rate,blood pressure 0.5 hours after surgery,anxiety scores 1 day before and 3 days after surgery,and the total number of complications in the observation group were all lower than those in the control group(P<0.05).Conclusion:The development of a nursing cooperation path in the operating room can help patients undergoing laparoscopic hysterectomy reduce heart rate,blood pressure,stress responses,and the risk of complications,and is worthy of promotion.
基金supported by the National Natural Science Foundation of China(No.62173274)the National Key R&D Program of China(No.2019YFA0405300)+4 种基金the Natural Science Foundation of Hunan Province of China(Nos.2021JJ10045 and 2025JJ60072)the Open Research Subject of State Key Laboratory of Intelligent Game(No.ZBKF-24-01)the Postdoctoral Fellowship Program of CPSF(No.GZB20240989)the China Postdoctoral Science Foundation(No.2024M754304)the Aeronautical Science Foundation of China(No.2023Z005030001).
文摘Cooperative guidance is a method for achieving combat objectives through information sharing and cooperative effects,and has emerged as a significant research area in the fields of missile guidance and systematic warfare.This study presents a systematic review and analysis of current research on cooperative guidance.First,a bibliometric analysis is conducted on 513 articles using the Scopus database and CiteSpace software to assess keyword clustering,keyword cooccurrence,and keyword burst,and to later visualize the results.Second,fundamental theories of cooperative guidance,including relative motion modeling methods,algebraic graph theory,and multi-agent consensus theory,are summarized.Subsequently,an overview of current cooperative laws and corresponding analysis methods is provided,with categorization based on the cooperative structure and convergence performance.Finally,we summarize current research developments based on five perspectives and propose a developmental framework based on five layers(cyber,physical,decision,information,and system),discussing potential future advancements in cooperative terminal guidance.This framework emphasizes five key areas of research:networked,heterogeneous,integrated,intelligent,and group cooperations,with the goal of offering trends and insights for futurework.
基金General Project of Philosophy and Social Sciences Research in Universities of Jiangsu Province,2024(2024SJYB1650).
文摘Under the background of"Digital Commerce for Rural Vitalization",rural E-commerce has experienced rapid development.However,agricultural products like strawberries,often produced by small-scale,fragmented,and less competitive individual farmers,struggle to meet the compliance and scalability demands of E-commerce,thereby constraining high-quality local economic development.Aiming to address this issue,this paper,guided by relevant policies and strategies,employs case analysis and logical deduction to explore the industrialization path of the"Cooperative+E-commerce"model for the strawberry industry.The research finds that by optimizing the cooperative's organizational structure,implementing multi-channel E-commerce strategies,upgrading the supply chain(including cold chain and quality traceability),and engaging in collaborative brand building,a robust industrial system can be formed.Supplemented by benefit evaluation,policy support,and regulatory oversight,this system can effectively bridge small-scale production with the broader market.This study concludes that this pathway can enhance the added value of the strawberry industry,increase farmer incomes,and provide practical insights for promoting high-quality local economic development.
基金supported in part by the National Natural Science Foundation of China(Grant Nos.62203246 and 62003127)Shandong Provincial Natural Science Foundation(Grant No.ZR2024QF041)the Natural Science Foundation of Hebei Province(Grant No.F2023202060)。
文摘Virtual coupling is a novel technology that enables trains to run closely together without physical connections through communication and automation systems.The paper addresses an adaptive polynomial approximation algorithm for the cooperative control of high-speed trains(HSTs)under virtual coupling.It aims to solve the cooperative tracking control problem of HST formation operations under various scenarios,including known and unknown parameters.To enable the HST formation system to achieve cooperative operation while ensuring an appropriate spacing distance,the tracking errors of displacement and speed throughout the entire operation converge to zero.The proposed control strategy focuses on adopting polynomial approximation to handle unknown parameters,which are estimated via adaptive laws.Additionally,the unknown parameters of the HSTs are estimated online through adaptive laws.Experimental results verify the effectiveness of this method.
基金supported in part by the Advanced Equipment Manufacturing Technology Innovation Project of Hebei Province under Grant No.22311801D,23311807D,and 236Z1816Gin part by the National Natural Science Foundation of China under Grant No.U20A20283.
文摘In this paper,a novel cooperative collision avoidance control strategy with relative velocity information for redundant robotic manipulators is derived to guarantee the behavioral safety of robots in the cooperative operational task.This strategy can generate the collision-free trajectory of the robotic links in real-time,which is to realize that the robot can avoid moving obstacles less conservatively and ensure tracking accuracy of terminal end-effector tasks in performing cooperative tasks.For the case where there is interference between the moving obstacle and the desired path of the robotic end-effector,the method inherits the null-space-based self-motion characteristics of the redundant manipulator,integrates the relative motion information,and uses the improved artificial potential field method to design the control items,which are used to generate the collision avoidance motion and carry out moving obstacles smoothly and less conservatively.At the same time,the strategy maintains the kinematic constraint relationship of dual-arm cooperatives,to meet the real-time collision avoidance task under collaborative tasks.Finally,the algorithm simulation indicates that the method can better ensure the tracking accuracy of the end-effector task and carry out moving obstacles smoothly.The experimental results show that the method can generate the real-time collision-free trajectory of the robot in the cooperative handling task,and the joint movement is continuous and stable.
基金Supported by the National Natural Science Foundation of China under Grant No 10575055the K.C.Wong Magna Fund in Ningbo University,and the Super-computer Center of Ningbo University.
文摘We studied the effect of population density in a spatial public goods game.We found that the effect on the evolution of cooperation is very complex when the strategy learning and mobility of players in a long range are considered in a two-dimensional lattice.As the learning range is larger than the mobility range,the system is driven to enter into a cooperation state for a low population density,because a small local group is beneficial to sustain a high level of cooperation.As population density increases to a moderate range,the mobility of players from a domain invaded by defectors supports the evolution stability of cooperation.When the mobility range is larger than the learning range,a formation of compact domains of cooperators promotes cooperation as the population density becomes high.
文摘The domain of foreign economic and technological cooperation in Shandong Province covers a very wide range of items. Developing its export-oriented economy, the province will focus on actively expanding the use of foreign funds to operate foreigninvested and overseas
文摘China s cooperation with Brazil, one of the largest countries in the third world, in the areas of space technology development and application has a great significance in the world. A joint program for the development of earth resources satellites is briefly introduced in this article.
文摘This paper reviews a local anesthesia for resection of back mass, and the rescue of patients with sudden apnea during the operation. It also summarizes the nursing experience and shortcomings of the visiting nurses during the operation, which provides relevant experience for the future local anesthesia operation for patients with cardiovascular complications. The patient underwent left back mass resection under local anesthesia. Blood pressure, heart rate and blood oxygen saturation were monitored. The right lateral position was adopted during the operation. During the 5-minute operation to separate the tumor, the visiting nurse noticed that the patient was pale and weak in answering the questions, and immediately she cried out. The ECG monitor showed that the heart rate was 45 beats/min and the SpO2 was 85%, with continuous decrease. Immediately call the surgeon to stop the operation. Change the patient from lateral position to supine position. Due to the timely rescue and proper measures, the patients heart rate rose to 70 beats/min, BP120/70mmHg, R22 beats/min, SpO2 was 98% after about 10 minutes. The patient regained consciousness and was able to correctly answer the questions. After 15 minutes of observation, the patients condition was stable and there was no discomfort. The right lateral decubitus position was placed again and the operation was completed after the drape was disinfected again. Conclusion: local anesthesia operation has certain risks. Attention should be paid to local anesthesia operation for patients with cardiovascular and other complications. Preoperative preparation should be adequate, peripheral veins should be opened regularly, and ECG and blood pressure should be monitored. During the operation, the patients complexion, consciousness and breathing were closely observed. If there is any abnormal situation, the surgeon should be reported in time and the emergency plan should be started to ensure the safety of the patients during the operation and to improve the quality of nursing cooperation during the operation.
基金The National Natural Science Foundation of China ( No.60872004, 60972026)the Important National Science and Technology Specific Projects (No. 2010ZX03006-002-01)the Research Fund of the National Mobile Communications Research Laboratory of Southeast University (No.2010A08)
文摘In order to improve network connectivity in clustered wireless sensor networks,a node cooperative algorithm based on virtual antenna arrays is proposed.All the nodes in the network are assumed to be clustered via Poisson Voronoi tessellation（PVT）.The activation of the node cooperative algorithm is determined by the cluster heads（CHs） according to communication links.When the cooperative algorithm is activated,the CH selects cooperative nodes（CNs） from its members to form a virtual antenna array.With the cooperation,nodes can extend the inter-cluster communication range to directly contact with further nodes after a coverage hole is detected,or compensate for channel gains while inter-cluster transmission fails due to deep channel fading.Simulation results show that the proposed algorithm achieves better network connectivity and energy efficiency.It can reduce outage probability,sustain network connectivity and maintain operations as long as possible,which prolongs network operation time.
基金supported in part by the National Natural Science Foundation of China(Nos.61671031,61722102,91738301)。
文摘With the rapid development of Unmanned Aerial Vehicle(UAV)technology,one of the emerging fields is to utilize multi-UAV as a team under autonomous control in a complex environment.Among the challenges in fully achieving autonomous control,Cooperative task assignment stands out as the key function.In this paper,we analyze the importance and difficulties of multiUAV cooperative task assignment in characterizing scenarios and obtaining high-quality solutions.Furthermore,we present three promising directions for future research:Cooperative task assignment in a dynamic complex environment,in an unmanned-manned aircraft system and in a UAV swarm.Our goal is to provide a brief review of multi-UAV cooperative task assignment for readers to further explore.
文摘Taking three typical farmers' specialized cooperatives in Jingyuan County of Gansu Province as example,this paper compared with the operating mode of three cooperatives and their position in the agricultural industry chain,and analyzed operating characteristics,problems,and similarities of three cooperatives and their functions in the agricultural industry chain.The study indicated that the farmers' specialized cooperatives can accurately find their position in the agricultural industry chain.This is helpful for raising their comprehensive competitiveness and it is very important to manage the survival and development of farmers' specialized cooperatives,which is of utmost importance to their effective operation.According to this study,the government should strengthen its support,speed up the cultivation of new-type professional farmers,while farmers' specialized cooperatives should grasp the operating characteristics,locate themselves and integrate multi-resources.These are effective measures for promoting healthy operation of farmers' specialized cooperatives.
文摘In relay-assisted cooperative communication,relay nodes help forwarding the information of a source node in case of link failure between the source and a destination.Although user cooperation improves the overall efficiency of the network,it requires incentive to stimulate potential relay nodes to assist the source by forwarding its data to the destination.Moreover,the potential relays are better informed than the source about their channel conditions to destination,which results in asymmetric information between the source and the relays.In this paper,we study the problem of lack of forwarding incentive in cooperative communication when channel state information of relays is private information and not known by the source.To tackle this problem,we apply the principle of contract theory to a cooperative wireless system.Source first designs incentive compatible and individually rational contract,consisting of a set of power-credit pairs.Then it broadcasts contract items to nearby nodes.Once the source node receives reply messages from the volunteer relays,it chooses one or more relays based on its requirements and communication starts.Simulation results show how credit assignment works in order to stimulate relays to cooperate and prevents relays from cheating behavior.
基金Supported by Research on Scientific Renovation and Sustainable Economic Development (Program of Humanities and Social Science Foundation of the Ministry of Education,09YJA790080)Systematic Analysis of Agricultural Scientific and Technological Progress in Jilin Province (the "Eleventh Five-year" Research Program of Social Science of Jilin Department of Education)Operation Design of Farmers'Professional Cooperatives in Gongzhuling City (Undergraduates' Inno-vative Experiment Program of Jilin University,2010C83280)
文摘Establishment of farmers' professional cooperatives is an effective approach of settling conflicts between small-scale production of rural households and great market, however, there are still many problems such as low level of standardization, unscientific market positioning, poor capacity of mitigating risks, and unfavorable ecological benefits. This study, based on field investigation data and successful support experience, further explored operation and management problems existing in Jilin Farming Cooperative, and proposed pertinent solutions so as to enhance the high-efficiency and standard operation of farmers' professional cooperatives in Jilin Province and even China.
文摘In this paper, we consider cooperative hyperbolic systems involving Schr?dinger operator defined on ?Rn. First we prove the existence and uniqueness of the state for these systems. Then we find the necessary and sufficient conditions of optimal control for such systems of the boundary type. We also find the necessary and sufficient conditions of optimal control for same systems when the observation is on the boundary.
基金Supported by Soft Science Research Project of Jilin Provincial Department of Science and Technology(20130420030FG)Project of Yanbian University(201216)
文摘After six years of development,the number of farmer cooperatives in Yanbian area was increased from 72 in 2007 to 2600 in 2012.It has become an important part of local modern agricultural operation.Through the survey and research of current status of farmer cooperatives in Yanbian area,we analyze the deficiencies in capital,technology and human resources during the operating to thoroughly understand its operating status.On this basis,we put forth some recommendations for the development of farmer cooperatives in Yanbian area:implementing industrialization operation;developing long-term development strategy;seeking the support of research institutions and colleges;increasing the types of services;enhancing the value-added.
文摘Control systems are being changed from wired to wireless communications because of flexibility, mobility and extensibility of wireless communication systems;however the reliability of wireless communications is suspected. In this paper, we propose cooperative communication scheme for wireless control systems which consist of a controller and multiple machines;these machines cooperatively work in a group and for the same duty. In the proposed method, the controller can communicate with machines directly or via other machines, whereas in the conventional method, the controller only communicates with machines directly. The simple 2-link arm plant is used to evaluate our proposed system, and the simulation results indicate that the proposed method is more accurate, and more stable than the conventional method.
文摘We conduct questionnaire survey of migrant workers in Wenjiang District and Jintang County of Chengdu City,respectively,using the method of key-point investigation and the sampling survey. We describe the status quo of the sample migrant workers' participation in the New Rural Cooperative Medical System,analyze the issues concerning migrant workers' participation in the New Rural Cooperative Medical System,and put forward the countermeasures and recommendations as follows: using many types of medical insurance; establishing universal reimbursement points in strange land and premium-paying system for migrant workers; making the proportion of reimbursement open and transparent; establishing and improving medicare security system for migrant workers.
