LEO satellite communication network has a large number of satellites distributed in low orbits,which leads to multiple coverage of many areas on the ground.It is hard work to describe and evaluate the reliability of L...LEO satellite communication network has a large number of satellites distributed in low orbits,which leads to multiple coverage of many areas on the ground.It is hard work to describe and evaluate the reliability of LEO satellite communication network.To solve this problem,the reliability of all-user terminals in LEO satellite communication network is defined,and the corresponding reliability evaluation method is proposed in the paper.Due to the large scale of the interstellar network,a modular reduction algorithm using the modular network instead of the original network for state decomposition is proposed in this paper.Case study shows that the calculation time of the proposed method is equivalent to 6.28%of the original state space decomposition algorithm.On this basis,the reliability of LEO satellite communication network is further analyzed.It is found that the reliability of LEO satellite network was more sensitive to the reliability of Inter-Satellite link and the satisfaction of global coverage in the early stage,and it is more sensitive to the reliability of the satellite in the later stage.The satellite-ground link has a relatively constant impact on of LEO satellite network.展开更多
Airborne communication terminal is a key unit in Ad hoc network of aircrafts. This paper mainly focuses on its implementation by embedded system, which is based on Samsung S3C2410 chip. System architecture, Linux tail...Airborne communication terminal is a key unit in Ad hoc network of aircrafts. This paper mainly focuses on its implementation by embedded system, which is based on Samsung S3C2410 chip. System architecture, Linux tailoring and touch-screen driver design are discussed in detail. Considering the requirements of stability and efficiency of the operating system, dynamic driver-loading method was employed firstly and only the necessary library files were transplanted to assist and test. The drivers finally were directly put into kernel configuration and then an integrated kernel was transplanted. Regarding to the problem of positioning issues on touch-screen, which is implemented in this system, an accurate positioning method is also presented.展开更多
This paper describes current situation and special requirements of local electric power communication network in China. The paper discusses the disadvantages of SDH and fiber loop carrier system applied to electric po...This paper describes current situation and special requirements of local electric power communication network in China. The paper discusses the disadvantages of SDH and fiber loop carrier system applied to electric power communication network. It presents a new Communication System-IDS-2000 integrated digital communication system. The paper introduces the characteristics and application of IDS-2000 system in the local electric power communication network.展开更多
The free space optical communication plays an important role in space-terrestrial integrated network due to its advantages including great improvement of data rate performance,low cost,security enhancement when compar...The free space optical communication plays an important role in space-terrestrial integrated network due to its advantages including great improvement of data rate performance,low cost,security enhancement when compared with conventional radio frequency(RF) technology.Meanwhile,CubeSats become popular in low earth orbit(LEO) network because of the low cost,fast response and the possibility of constituting constellations and formations to execute missions that a single large satellite cannot do.However,it is a difficult task to build an optical communication link between the CubeSats.In this paper,the cuttingedge laser technology progress on the CubeSats is reviewed.The characters of laser link on the CubeSat and the key techniques in the laser communication terminal(LCT) design are demonstrated.展开更多
The posterior communicating artery (PCoA) arises from the cerebral part of the internal carotid artery and reaching the interpeduncular cistern unites with the posterior cerebral artery, marking the beginning of its p...The posterior communicating artery (PCoA) arises from the cerebral part of the internal carotid artery and reaching the interpeduncular cistern unites with the posterior cerebral artery, marking the beginning of its post-communicating part. We accidentally found a case of an unusual origin and termination of the right PCoA associated with a presence of the right olfactory artery remnant in a 35-year-old male cadaver routinely dis-sected at Institute of Forensic Medicine. Presented vascular variations have not been reported previously in the literature. In the event of PCoA origin from the right middle cerebral artery normally developed from the cra-nial end of primitive internal carotid artery, as well as the PCoA junction with basilar tip, this PCoA could be the most cranial carotid-basilar anastomosis. Simultaneously, here presented right olfactory artery remnant could be the third variant of this persistent embryonic artery.展开更多
基金supported by the projects of the National Natural Science Foundation of China entitled“Reliability growth evaluation and prediction model of large aerospace(72071111)”“Reverse multi variable CF-GERT model and its application for complex equipment development schedule under the background of multi project mixed batch(71801127)”+4 种基金“Research on network of reliability growth of complex equipment under the background of collaborative development(71671091)”supported by a joint project of both the NSFC and the RS of the UK entitled“On grey dynamic scheduling model of complex product based on sensing information of internet of things”(71811530338)support of the Fundamental Research Funds for the Central Universities of China(NC2019003,NP2019104)Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX210239)support of a project of Intelligence Introduction Base of the Ministry of Science and Technology(G20190010178).
文摘LEO satellite communication network has a large number of satellites distributed in low orbits,which leads to multiple coverage of many areas on the ground.It is hard work to describe and evaluate the reliability of LEO satellite communication network.To solve this problem,the reliability of all-user terminals in LEO satellite communication network is defined,and the corresponding reliability evaluation method is proposed in the paper.Due to the large scale of the interstellar network,a modular reduction algorithm using the modular network instead of the original network for state decomposition is proposed in this paper.Case study shows that the calculation time of the proposed method is equivalent to 6.28%of the original state space decomposition algorithm.On this basis,the reliability of LEO satellite communication network is further analyzed.It is found that the reliability of LEO satellite network was more sensitive to the reliability of Inter-Satellite link and the satisfaction of global coverage in the early stage,and it is more sensitive to the reliability of the satellite in the later stage.The satellite-ground link has a relatively constant impact on of LEO satellite network.
文摘Airborne communication terminal is a key unit in Ad hoc network of aircrafts. This paper mainly focuses on its implementation by embedded system, which is based on Samsung S3C2410 chip. System architecture, Linux tailoring and touch-screen driver design are discussed in detail. Considering the requirements of stability and efficiency of the operating system, dynamic driver-loading method was employed firstly and only the necessary library files were transplanted to assist and test. The drivers finally were directly put into kernel configuration and then an integrated kernel was transplanted. Regarding to the problem of positioning issues on touch-screen, which is implemented in this system, an accurate positioning method is also presented.
文摘This paper describes current situation and special requirements of local electric power communication network in China. The paper discusses the disadvantages of SDH and fiber loop carrier system applied to electric power communication network. It presents a new Communication System-IDS-2000 integrated digital communication system. The paper introduces the characteristics and application of IDS-2000 system in the local electric power communication network.
文摘The free space optical communication plays an important role in space-terrestrial integrated network due to its advantages including great improvement of data rate performance,low cost,security enhancement when compared with conventional radio frequency(RF) technology.Meanwhile,CubeSats become popular in low earth orbit(LEO) network because of the low cost,fast response and the possibility of constituting constellations and formations to execute missions that a single large satellite cannot do.However,it is a difficult task to build an optical communication link between the CubeSats.In this paper,the cuttingedge laser technology progress on the CubeSats is reviewed.The characters of laser link on the CubeSat and the key techniques in the laser communication terminal(LCT) design are demonstrated.
基金supported by Ministry of Science and Technological Development of Republic of Serbia(contract grant numbers:41018 and 175092).
文摘The posterior communicating artery (PCoA) arises from the cerebral part of the internal carotid artery and reaching the interpeduncular cistern unites with the posterior cerebral artery, marking the beginning of its post-communicating part. We accidentally found a case of an unusual origin and termination of the right PCoA associated with a presence of the right olfactory artery remnant in a 35-year-old male cadaver routinely dis-sected at Institute of Forensic Medicine. Presented vascular variations have not been reported previously in the literature. In the event of PCoA origin from the right middle cerebral artery normally developed from the cra-nial end of primitive internal carotid artery, as well as the PCoA junction with basilar tip, this PCoA could be the most cranial carotid-basilar anastomosis. Simultaneously, here presented right olfactory artery remnant could be the third variant of this persistent embryonic artery.
