Taking“Friendly Shandong”official account as an example,the relevant data of the account on the four platforms of Tiktok,Kwai,Bilibili and Little Red Book were comparatively analyzed to study the influence of short ...Taking“Friendly Shandong”official account as an example,the relevant data of the account on the four platforms of Tiktok,Kwai,Bilibili and Little Red Book were comparatively analyzed to study the influence of short video on the communication of Shandong tourism image.The research mainly included two aspects:fan persona features and interactive effects.Through comparative study,it will provide a reference for the operation team of“Friendly Shandong”official account to spread the tourism image of Shandong with different platforms.展开更多
This paper discusses the significance and prospects of low altitude small satellite aerial vehicles to ensure smooth aerial-ground communications for next-generation broadband networks.To achieve the generic goals of ...This paper discusses the significance and prospects of low altitude small satellite aerial vehicles to ensure smooth aerial-ground communications for next-generation broadband networks.To achieve the generic goals of fifthgeneration and beyondwireless networks,the existing aerial network architecture needs to be revisited.The detailed architecture of low altitude aerial networks and the challenges in resource management have been illustrated in this paper.Moreover,we have studied the coordination between promising communication technologies and low altitude aerial networks to provide robust network coverage.We talk about the techniques that can ensure userfriendly control and monitoring of the low altitude aerial networks to bring forth wireless broadband connectivity to a new dimension.In the end,we highlight the future research directions of aerial-ground communications in terms of access technologies,machine learning,compressed sensing,and quantum communications.展开更多
This study examines the impact of communication on investors’trading frequency based on a unique dataset drawn from a Chinese social trading platform.We find robust evidence that real-account portfolio owners on the ...This study examines the impact of communication on investors’trading frequency based on a unique dataset drawn from a Chinese social trading platform.We find robust evidence that real-account portfolio owners on the platform trade more frequently under the influence of the comments posted by their leaders(the owners of portfolios they have followed).Moreover,portfolio owners are more sensitive to the quantity than to the tone of leaders’comments.Finally,both trading frequency and leaders’comments negatively impact portfolio owners’future performance.Our find-ings support the notion that social interaction promotes active investment strategies.展开更多
CHEN Haoyong made the decision to devote himself to the development of electrical power science while he was majoring in electrical engineering at the Xi’an Jiaotong University in the early 1990s.In 1994,his professo...CHEN Haoyong made the decision to devote himself to the development of electrical power science while he was majoring in electrical engineering at the Xi’an Jiaotong University in the early 1990s.In 1994,his professor introduced him to Wang Xifan,a famous scholar in the field of power systems who had just returned from Japan and who was also an academician of the Chinese Academy of Sciences.Over the following 12 years,Chen studied and worked under the BY ZHANG LI Building a Communication and Cooperation Platform for Chinese Scientists guidance and supervision of Wang.展开更多
Computer supported cooperative work as a new multi disciplinary research area, brings a lot of new challenges for the computer technologies. Having analyzed the CSCW applications by using the groupware space time mat...Computer supported cooperative work as a new multi disciplinary research area, brings a lot of new challenges for the computer technologies. Having analyzed the CSCW applications by using the groupware space time matrix, we conclude that the communicatio展开更多
In this study,a mathematical model of multipath channels is established,and the delay parameters of 10-path models are calculated at 300 m.A multipath-channel hardware simulator based on a field programmable gate arra...In this study,a mathematical model of multipath channels is established,and the delay parameters of 10-path models are calculated at 300 m.A multipath-channel hardware simulator based on a field programmable gate array(FPGA)is designed and verified at 100 k Hz,200 k Hz,500 k Hz,1 MHz,and 24 MHz transmission frequencies.According to the characteristics of the ocean induction coupling chain channel,the orthogonal frequency-division multiplexing(OFDM)algorithm parameters are designed by referring to the wireless communication protocol.The appropriate length cyclic prefix(CP)is added in the OFDM symbol to resist the multipath effect of the seawater channel,and the FPGA hardware transceiver based on the OFDM algorithm is realized.The hardware platform of the ocean induction coupling chain communication system is developed to resist the multipath effect of the seawater channel and tested at 24 MHz.The experimental results show that 800 ns is the best CP length for the developed system,which can effectively resist the multipath effect,with a signal-to-noise ratio above 24 d B and a bit error rate below 1%.This study provides a hardware simulation test platform and an effective method to resist the multipath effect of a seawater channel and improve the transmission performance of the seawater channel.展开更多
In order to support CSCW (Computer Supported Cooperative Work) applications, some basic technologies must be introduced into the computer supported environment. They are shared workspace, work management and interacti...In order to support CSCW (Computer Supported Cooperative Work) applications, some basic technologies must be introduced into the computer supported environment. They are shared workspace, work management and interaction among participants. Computer communication is essential and important for these technologies. In this paper, we will discuss different kinds of communication services required by CSCW. There are three communication styles in CSCW support environment: real time stream transfer, real time block transfer and non real time transfer. These communication services require different QoS quality of service parameters. The architecture of QoS is then analyzed and a framework of a QoS guaranteed communication service platform is proposed.展开更多
The airspace communication network based on spacecraft has a wide range of applications in regional information enhancement and emergency communication. In this paper, a routing algorithm for congestion degree detecti...The airspace communication network based on spacecraft has a wide range of applications in regional information enhancement and emergency communication. In this paper, a routing algorithm for congestion degree detection of multipath routing (CD_AOMDV) is proposed. The method of combining the whole congestion degree detection and local congestion degree detection before service initiation is adopted. Timely and accurate judgment of the congestion degree reduced the loss rate of the hot nodes, so the average packet loss rate reduced. Simulation results show that compared with the traditional AOMDV protocol, the CD_AOMDV proposed in this paper has reduced the packet loss and improved delay performance, which is more suitable for the airspace communication network.展开更多
An inevitable trend has already taken shape for the application of the 5th Generation Mobile Communication Technology(5G)in the railway sector.The application scenarios and business types of the railway sector are com...An inevitable trend has already taken shape for the application of the 5th Generation Mobile Communication Technology(5G)in the railway sector.The application scenarios and business types of the railway sector are complex and diverse,so it is indispensable to test and verify the railway 5G before actual deployment.The design and creation of the railway 5G integrated innovation test platform provides engineering design,test and verification conditions for the networking,coverage and business development of 5G public networks and 5G-R in railway scenarios.This paper introduces the design of the overall architecture for the integrated railway 5G innovation test platform according to the railway network requirements,application scenarios and intelligent development trend;respectively elaborates on the design of the 5G-R core network,bearer network and wireless access along loop tracks,in combination with the characteristics of railway scenarios and the requirements of railway dispatching,operation and safety;raises further solutions on the network deployment and coverage schemes of 5G public networks so as to meet the application requirements of 5G public networks.The study results show that the integrated railway 5G innovation test platform scheme contains co-existence of 5G public and private networks,combines the indoor and outdoor scenarios,as well as takes into account of the dynamic and static tests so as to meet the environmental requirements for the integrated railway 5G test and application of all network functions,for which it can provide comprehensive technical support for railway 5G technology research and development,standard formulation,testing,etc.展开更多
In today’s college English extracurricular learning,college students often neglect the combination of English language learning and the input of Chinese traditional cultural knowledge,paying too much attention to Wes...In today’s college English extracurricular learning,college students often neglect the combination of English language learning and the input of Chinese traditional cultural knowledge,paying too much attention to Western culture learning,ignoring their traditional culture and lead to be speechless when encountering cultural exchange activities.The author believes that college students should pay attention to the input of Chinese traditional cultural content in the process of independent English learning outside the classroom.The creative team of college students led by the author through the WeChat platform,in Xinjiang Agricultural University,conducted a combination of Chinese culture input and English autonomous learning,aiming at strengthening the effectiveness of English learning,improving the self-learning ability and intercultural communication skills.展开更多
The adoption of Internet of Things(IoT)sensing devices is growing rapidly due to their ability to provide realtime services.However,it is constrained by limited data storage and processing power.It offloads its massiv...The adoption of Internet of Things(IoT)sensing devices is growing rapidly due to their ability to provide realtime services.However,it is constrained by limited data storage and processing power.It offloads its massive data stream to edge devices and the cloud for adequate storage and processing.This further leads to the challenges of data outliers,data redundancies,and cloud resource load balancing that would affect the execution and outcome of data streams.This paper presents a review of existing analytics algorithms deployed on IoT-enabled edge cloud infrastructure that resolved the challenges of data outliers,data redundancies,and cloud resource load balancing.The review highlights the problems solved,the results,the weaknesses of the existing algorithms,and the physical and virtual cloud storage servers for resource load balancing.In addition,it discusses the adoption of network protocols that govern the interaction between the three-layer architecture of IoT sensing devices enabled edge cloud and its prevailing challenges.A total of 72 algorithms covering the categories of classification,regression,clustering,deep learning,and optimization have been reviewed.The classification approach has been widely adopted to solve the problem of redundant data,while clustering and optimization approaches are more used for outlier detection and cloud resource allocation.展开更多
Many Internet of Things(IoT)systems are based on the intercommunication among different devices and centralized systems.Nowadays,there are several commercial and research platforms available to simplify the creation o...Many Internet of Things(IoT)systems are based on the intercommunication among different devices and centralized systems.Nowadays,there are several commercial and research platforms available to simplify the creation of such IoT systems.However,developing these systems can often be a tedious task.To address this challenge,a proposed solution involves the implementation of a unified program or script that encompasses the entire system,including IoT devices functionality.This approach is based on an abstraction,integrating the control of the devices in a single program through a programmable object.Subsequently,the proposal processes the unified script to generate the centralized system code and a controller for each device.By adopting this approach,developers will be able to create IoT systems with significantly reduced implementation costs,surpassing current platforms by more than 10%.The results demonstrate that the single program approach can significantly accelerate the development of IoT systems relying on device communication.展开更多
In order to ensure that a mobile launch platform is able to transport a launch vehicle which is assembled vertically on a complex orbit,a communication network for the drive control system was designed.Based on the ch...In order to ensure that a mobile launch platform is able to transport a launch vehicle which is assembled vertically on a complex orbit,a communication network for the drive control system was designed.Based on the char-acteristics of equipment of the drive control system and its position,Industrial Ethernet and Profibus were selected.To meet the requirements for reliability and maintainability of aerospace products,the communication network featured a hot redundant to avoid single point failure risk,so that if any point in the system fails,the control strategy of standby switches using heartbeat detection and parity check would ensure the normal communication and failure diagnostics,which could enable the transport mission of the launch vehicle to be completed smoothly.展开更多
With the improvement of the degree of aging,the traditional pension model can no longer meet the growing needs of the elderly.Therefore,it is necessary to use the intelligent means of information technology to improve...With the improvement of the degree of aging,the traditional pension model can no longer meet the growing needs of the elderly.Therefore,it is necessary to use the intelligent means of information technology to improve the level of pension services.This paper will integrate multi-sensor fusion technology,NB-IoT communication technology and cloud platform technology to develop and design a smart pension online monitoring system to realize real-time collection of human health and motion status information and realize monitoring platform management.In this system,STM32 microcontroller will be used as the main control module,and MAX30102,ADXL345 and DS18B20 sensors will be used to collect the heart rate,blood oxygen,displacement and body temperature of the human body in real time.On the one hand,the communication part is completed by the BC20 Internet of Things module.The data transmission between the terminal detection device and the cloud platform,on the other hand,the HC-42 Bluetooth module is used to complete the data communication with the mobile phone.The test results show that the system can collect and process data accurately in real time and maintain good communication with the cloud platform and mobile phone.The designed system has strong pertinence,easy operation,high reliability and broad development prospects.展开更多
Free-space laser communication is characterized by high communication speed, strong anti-jamming ability, high confidentiality, and flexible configuration. In this paper, a pointing, acquisition, and tracking (PAT) sy...Free-space laser communication is characterized by high communication speed, strong anti-jamming ability, high confidentiality, and flexible configuration. In this paper, a pointing, acquisition, and tracking (PAT) system based on a two-stage (i.e., coarse and fine) composite tracking mechanism is proposed to solve the optical axis alignment problem, which is common in free-space laser communications. The acquisition probability of the PAT system is ensured by designing two tracking modules, a coarse tracking module which combines passive damping with active suppression and a fine tracking module based on an electromagnetic galvanometer. Both modules are combined by using a dynamic scanning mechanism based on the gyroscope signal. Finally, a free-space laser communication test with a long range and a high speed is conducted by two fixed-wing Y12 aircrafts equipped with the proposed PAT system. Experimental results show that the coarse tracking precision of the airborne PAT system is 10 μrad (1σ), and the fine tracking precision is 10μrad (1σ) during flights which are much improved as compared with the indoor tests. This indicates that the system can achieve a high precision for PAT during high-speed and long-range laser communications in the free-space. This also verifies the tracking capability and the environmental adaptability of the proposed laser communication PAT system.展开更多
GENERAL Asian Pacific Journal of Tropical Biomedicine is sponsored by Hainan Medical University Journal Publisher, and aims to set up an acdemic communicating platform for scientists all over the world on tropical bio...GENERAL Asian Pacific Journal of Tropical Biomedicine is sponsored by Hainan Medical University Journal Publisher, and aims to set up an acdemic communicating platform for scientists all over the world on tropical biomedicine and related sciences.The Journal invites concise reports of original research in all areas of tropical biomedicine and related fields, both experimental and clinical, including modern, traditional and epidemiological studies, from any part of the world.展开更多
GENERAL Asian Pacific Journal of Tropical Biomedicine is sponsored by Hainan Medical University Journal Publisher,and aims to set up an acdemic communicating platform for Chinese and scientists all over the world on t...GENERAL Asian Pacific Journal of Tropical Biomedicine is sponsored by Hainan Medical University Journal Publisher,and aims to set up an acdemic communicating platform for Chinese and scientists all over the world on tropical biomedicine and related sciences.The Journal invites concise reports of original research in all areas of tropical biomedicine and related fields,both experimental and clinical,including modern.展开更多
GENERAL Asian Pacific Journal of Tropical Biomedicine is sponsored by Hainan Medical University Journal Publisher,and aims to set up an acdemic communicating platform for scientists all over the world on tropical biom...GENERAL Asian Pacific Journal of Tropical Biomedicine is sponsored by Hainan Medical University Journal Publisher,and aims to set up an acdemic communicating platform for scientists all over the world on tropical biomedicine and related sciences.The Journal invites concise reports of original research in all areas of tropical biomedicine and related fields,both experimental and clinical,including modern,traditional and epidemiological studies,from any part of the world.展开更多
With the rapid development of global information highway,multimedia communication technology plays a more and more important role in national economic and social development.However,the multimedia communication sy... With the rapid development of global information highway,multimedia communication technology plays a more and more important role in national economic and social development.However,the multimedia communication system is a complicated real time distributed system and its software is difficult to develop.In order to improve the rapid development and application of the multimedia communication technology,there is an urgent need to carry out the basic research work of software development platform in this field.……展开更多
基金Social Science Planning Research Project of Shandong Province(22CLYJ34)Key Project of Shandong Art Science(23QR03280040)+1 种基金Social Science Project of Tai’an City(23YB061)First-class Undergraduate Courses of Tourism Markeing of Taishan University.
文摘Taking“Friendly Shandong”official account as an example,the relevant data of the account on the four platforms of Tiktok,Kwai,Bilibili and Little Red Book were comparatively analyzed to study the influence of short video on the communication of Shandong tourism image.The research mainly included two aspects:fan persona features and interactive effects.Through comparative study,it will provide a reference for the operation team of“Friendly Shandong”official account to spread the tourism image of Shandong with different platforms.
文摘This paper discusses the significance and prospects of low altitude small satellite aerial vehicles to ensure smooth aerial-ground communications for next-generation broadband networks.To achieve the generic goals of fifthgeneration and beyondwireless networks,the existing aerial network architecture needs to be revisited.The detailed architecture of low altitude aerial networks and the challenges in resource management have been illustrated in this paper.Moreover,we have studied the coordination between promising communication technologies and low altitude aerial networks to provide robust network coverage.We talk about the techniques that can ensure userfriendly control and monitoring of the low altitude aerial networks to bring forth wireless broadband connectivity to a new dimension.In the end,we highlight the future research directions of aerial-ground communications in terms of access technologies,machine learning,compressed sensing,and quantum communications.
基金National Natural Science Foundation of China(Grant No.7167030951).
文摘This study examines the impact of communication on investors’trading frequency based on a unique dataset drawn from a Chinese social trading platform.We find robust evidence that real-account portfolio owners on the platform trade more frequently under the influence of the comments posted by their leaders(the owners of portfolios they have followed).Moreover,portfolio owners are more sensitive to the quantity than to the tone of leaders’comments.Finally,both trading frequency and leaders’comments negatively impact portfolio owners’future performance.Our find-ings support the notion that social interaction promotes active investment strategies.
文摘CHEN Haoyong made the decision to devote himself to the development of electrical power science while he was majoring in electrical engineering at the Xi’an Jiaotong University in the early 1990s.In 1994,his professor introduced him to Wang Xifan,a famous scholar in the field of power systems who had just returned from Japan and who was also an academician of the Chinese Academy of Sciences.Over the following 12 years,Chen studied and worked under the BY ZHANG LI Building a Communication and Cooperation Platform for Chinese Scientists guidance and supervision of Wang.
文摘Computer supported cooperative work as a new multi disciplinary research area, brings a lot of new challenges for the computer technologies. Having analyzed the CSCW applications by using the groupware space time matrix, we conclude that the communicatio
基金supported by the National Key Research and Development Program of China(Nos.2017YFC1403403,2017YFC1403304)。
文摘In this study,a mathematical model of multipath channels is established,and the delay parameters of 10-path models are calculated at 300 m.A multipath-channel hardware simulator based on a field programmable gate array(FPGA)is designed and verified at 100 k Hz,200 k Hz,500 k Hz,1 MHz,and 24 MHz transmission frequencies.According to the characteristics of the ocean induction coupling chain channel,the orthogonal frequency-division multiplexing(OFDM)algorithm parameters are designed by referring to the wireless communication protocol.The appropriate length cyclic prefix(CP)is added in the OFDM symbol to resist the multipath effect of the seawater channel,and the FPGA hardware transceiver based on the OFDM algorithm is realized.The hardware platform of the ocean induction coupling chain communication system is developed to resist the multipath effect of the seawater channel and tested at 24 MHz.The experimental results show that 800 ns is the best CP length for the developed system,which can effectively resist the multipath effect,with a signal-to-noise ratio above 24 d B and a bit error rate below 1%.This study provides a hardware simulation test platform and an effective method to resist the multipath effect of a seawater channel and improve the transmission performance of the seawater channel.
文摘In order to support CSCW (Computer Supported Cooperative Work) applications, some basic technologies must be introduced into the computer supported environment. They are shared workspace, work management and interaction among participants. Computer communication is essential and important for these technologies. In this paper, we will discuss different kinds of communication services required by CSCW. There are three communication styles in CSCW support environment: real time stream transfer, real time block transfer and non real time transfer. These communication services require different QoS quality of service parameters. The architecture of QoS is then analyzed and a framework of a QoS guaranteed communication service platform is proposed.
文摘The airspace communication network based on spacecraft has a wide range of applications in regional information enhancement and emergency communication. In this paper, a routing algorithm for congestion degree detection of multipath routing (CD_AOMDV) is proposed. The method of combining the whole congestion degree detection and local congestion degree detection before service initiation is adopted. Timely and accurate judgment of the congestion degree reduced the loss rate of the hot nodes, so the average packet loss rate reduced. Simulation results show that compared with the traditional AOMDV protocol, the CD_AOMDV proposed in this paper has reduced the packet loss and improved delay performance, which is more suitable for the airspace communication network.
文摘An inevitable trend has already taken shape for the application of the 5th Generation Mobile Communication Technology(5G)in the railway sector.The application scenarios and business types of the railway sector are complex and diverse,so it is indispensable to test and verify the railway 5G before actual deployment.The design and creation of the railway 5G integrated innovation test platform provides engineering design,test and verification conditions for the networking,coverage and business development of 5G public networks and 5G-R in railway scenarios.This paper introduces the design of the overall architecture for the integrated railway 5G innovation test platform according to the railway network requirements,application scenarios and intelligent development trend;respectively elaborates on the design of the 5G-R core network,bearer network and wireless access along loop tracks,in combination with the characteristics of railway scenarios and the requirements of railway dispatching,operation and safety;raises further solutions on the network deployment and coverage schemes of 5G public networks so as to meet the application requirements of 5G public networks.The study results show that the integrated railway 5G innovation test platform scheme contains co-existence of 5G public and private networks,combines the indoor and outdoor scenarios,as well as takes into account of the dynamic and static tests so as to meet the environmental requirements for the integrated railway 5G test and application of all network functions,for which it can provide comprehensive technical support for railway 5G technology research and development,standard formulation,testing,etc.
文摘In today’s college English extracurricular learning,college students often neglect the combination of English language learning and the input of Chinese traditional cultural knowledge,paying too much attention to Western culture learning,ignoring their traditional culture and lead to be speechless when encountering cultural exchange activities.The author believes that college students should pay attention to the input of Chinese traditional cultural content in the process of independent English learning outside the classroom.The creative team of college students led by the author through the WeChat platform,in Xinjiang Agricultural University,conducted a combination of Chinese culture input and English autonomous learning,aiming at strengthening the effectiveness of English learning,improving the self-learning ability and intercultural communication skills.
文摘The adoption of Internet of Things(IoT)sensing devices is growing rapidly due to their ability to provide realtime services.However,it is constrained by limited data storage and processing power.It offloads its massive data stream to edge devices and the cloud for adequate storage and processing.This further leads to the challenges of data outliers,data redundancies,and cloud resource load balancing that would affect the execution and outcome of data streams.This paper presents a review of existing analytics algorithms deployed on IoT-enabled edge cloud infrastructure that resolved the challenges of data outliers,data redundancies,and cloud resource load balancing.The review highlights the problems solved,the results,the weaknesses of the existing algorithms,and the physical and virtual cloud storage servers for resource load balancing.In addition,it discusses the adoption of network protocols that govern the interaction between the three-layer architecture of IoT sensing devices enabled edge cloud and its prevailing challenges.A total of 72 algorithms covering the categories of classification,regression,clustering,deep learning,and optimization have been reviewed.The classification approach has been widely adopted to solve the problem of redundant data,while clustering and optimization approaches are more used for outlier detection and cloud resource allocation.
文摘Many Internet of Things(IoT)systems are based on the intercommunication among different devices and centralized systems.Nowadays,there are several commercial and research platforms available to simplify the creation of such IoT systems.However,developing these systems can often be a tedious task.To address this challenge,a proposed solution involves the implementation of a unified program or script that encompasses the entire system,including IoT devices functionality.This approach is based on an abstraction,integrating the control of the devices in a single program through a programmable object.Subsequently,the proposal processes the unified script to generate the centralized system code and a controller for each device.By adopting this approach,developers will be able to create IoT systems with significantly reduced implementation costs,surpassing current platforms by more than 10%.The results demonstrate that the single program approach can significantly accelerate the development of IoT systems relying on device communication.
文摘In order to ensure that a mobile launch platform is able to transport a launch vehicle which is assembled vertically on a complex orbit,a communication network for the drive control system was designed.Based on the char-acteristics of equipment of the drive control system and its position,Industrial Ethernet and Profibus were selected.To meet the requirements for reliability and maintainability of aerospace products,the communication network featured a hot redundant to avoid single point failure risk,so that if any point in the system fails,the control strategy of standby switches using heartbeat detection and parity check would ensure the normal communication and failure diagnostics,which could enable the transport mission of the launch vehicle to be completed smoothly.
基金supported by Jiangsu Provincial Natural Science Fund(BK20150247)the Fundamental Research Funds for Postgraduate Research&Practice Innovation Program of Jiangsu Province(XSJCX22_36,XSJCX22_44,SJCX22_1479)
文摘With the improvement of the degree of aging,the traditional pension model can no longer meet the growing needs of the elderly.Therefore,it is necessary to use the intelligent means of information technology to improve the level of pension services.This paper will integrate multi-sensor fusion technology,NB-IoT communication technology and cloud platform technology to develop and design a smart pension online monitoring system to realize real-time collection of human health and motion status information and realize monitoring platform management.In this system,STM32 microcontroller will be used as the main control module,and MAX30102,ADXL345 and DS18B20 sensors will be used to collect the heart rate,blood oxygen,displacement and body temperature of the human body in real time.On the one hand,the communication part is completed by the BC20 Internet of Things module.The data transmission between the terminal detection device and the cloud platform,on the other hand,the HC-42 Bluetooth module is used to complete the data communication with the mobile phone.The test results show that the system can collect and process data accurately in real time and maintain good communication with the cloud platform and mobile phone.The designed system has strong pertinence,easy operation,high reliability and broad development prospects.
基金the National Natural Science Foundation of China (Grant No. 51505087).
文摘Free-space laser communication is characterized by high communication speed, strong anti-jamming ability, high confidentiality, and flexible configuration. In this paper, a pointing, acquisition, and tracking (PAT) system based on a two-stage (i.e., coarse and fine) composite tracking mechanism is proposed to solve the optical axis alignment problem, which is common in free-space laser communications. The acquisition probability of the PAT system is ensured by designing two tracking modules, a coarse tracking module which combines passive damping with active suppression and a fine tracking module based on an electromagnetic galvanometer. Both modules are combined by using a dynamic scanning mechanism based on the gyroscope signal. Finally, a free-space laser communication test with a long range and a high speed is conducted by two fixed-wing Y12 aircrafts equipped with the proposed PAT system. Experimental results show that the coarse tracking precision of the airborne PAT system is 10 μrad (1σ), and the fine tracking precision is 10μrad (1σ) during flights which are much improved as compared with the indoor tests. This indicates that the system can achieve a high precision for PAT during high-speed and long-range laser communications in the free-space. This also verifies the tracking capability and the environmental adaptability of the proposed laser communication PAT system.
文摘GENERAL Asian Pacific Journal of Tropical Biomedicine is sponsored by Hainan Medical University Journal Publisher, and aims to set up an acdemic communicating platform for scientists all over the world on tropical biomedicine and related sciences.The Journal invites concise reports of original research in all areas of tropical biomedicine and related fields, both experimental and clinical, including modern, traditional and epidemiological studies, from any part of the world.
文摘GENERAL Asian Pacific Journal of Tropical Biomedicine is sponsored by Hainan Medical University Journal Publisher,and aims to set up an acdemic communicating platform for Chinese and scientists all over the world on tropical biomedicine and related sciences.The Journal invites concise reports of original research in all areas of tropical biomedicine and related fields,both experimental and clinical,including modern.
文摘GENERAL Asian Pacific Journal of Tropical Biomedicine is sponsored by Hainan Medical University Journal Publisher,and aims to set up an acdemic communicating platform for scientists all over the world on tropical biomedicine and related sciences.The Journal invites concise reports of original research in all areas of tropical biomedicine and related fields,both experimental and clinical,including modern,traditional and epidemiological studies,from any part of the world.
文摘 With the rapid development of global information highway,multimedia communication technology plays a more and more important role in national economic and social development.However,the multimedia communication system is a complicated real time distributed system and its software is difficult to develop.In order to improve the rapid development and application of the multimedia communication technology,there is an urgent need to carry out the basic research work of software development platform in this field.……