A measuring system for high-speed hydrogen ice pellet was introduced in this paper and the photographing of flying pellet taken therein. With the system, a pellet (minimum size of φ 0.3 mm) velocity (ranging from 50 ...A measuring system for high-speed hydrogen ice pellet was introduced in this paper and the photographing of flying pellet taken therein. With the system, a pellet (minimum size of φ 0.3 mm) velocity (ranging from 50 m/s to 2500 m/s) can be measured in the HL-1M tokamak fueling experiments. By analyzing photographs and the conditions of frozen pellets (including gas supply, gas replenishment, temperature controlling etc), the pellet-freezing technology is summarized in the paper.展开更多
With the rapid development of Peer-to-Peer(P2P) technology,IPTV applications based on that have received more and more attention from both industry and academia. Several applications using the data-driven mesh-pull ar...With the rapid development of Peer-to-Peer(P2P) technology,IPTV applications based on that have received more and more attention from both industry and academia. Several applications using the data-driven mesh-pull architectures raised and gained great success commercially. At present,PPLive system is one of the most popular instances of IPTV applications which attract a large number of users from across the globe. At the same time,however,the dramatic rise in popularity makes it more likely to become a vulnerable target. In this paper,we propose an effective measurement architecture,which is based on the peer's nature not only receiving polluted video chunks but also forwarding those to other peers,to measure the video streaming pollution attack and then use a dedicated crawler of PPLive developed by us to evaluate the impact of pollution in P2P live streaming. Specifically,the results show that a single polluter is capable of compromising all the system and its destructiveness is severe.展开更多
Light screen velocity measuring method with unique advantages has been widely used in the velocity measurement of various moving bodies.For large air resistance and friction force which the big moving bodies are subje...Light screen velocity measuring method with unique advantages has been widely used in the velocity measurement of various moving bodies.For large air resistance and friction force which the big moving bodies are subjected to during the light screen velocity measuring,the principle of velocity correction was proposed and a velocity correction equation was derived.A light screen velocity measuring method was used to measure the velocity of big moving bodies which have complex velocity attenuation,and the better results were gained in practical tests.The measuring uncertainty after the velocity correction was calculated.展开更多
文摘A measuring system for high-speed hydrogen ice pellet was introduced in this paper and the photographing of flying pellet taken therein. With the system, a pellet (minimum size of φ 0.3 mm) velocity (ranging from 50 m/s to 2500 m/s) can be measured in the HL-1M tokamak fueling experiments. By analyzing photographs and the conditions of frozen pellets (including gas supply, gas replenishment, temperature controlling etc), the pellet-freezing technology is summarized in the paper.
基金supported by the National 973 Key Basic Research Program under grant JG2008031
文摘With the rapid development of Peer-to-Peer(P2P) technology,IPTV applications based on that have received more and more attention from both industry and academia. Several applications using the data-driven mesh-pull architectures raised and gained great success commercially. At present,PPLive system is one of the most popular instances of IPTV applications which attract a large number of users from across the globe. At the same time,however,the dramatic rise in popularity makes it more likely to become a vulnerable target. In this paper,we propose an effective measurement architecture,which is based on the peer's nature not only receiving polluted video chunks but also forwarding those to other peers,to measure the video streaming pollution attack and then use a dedicated crawler of PPLive developed by us to evaluate the impact of pollution in P2P live streaming. Specifically,the results show that a single polluter is capable of compromising all the system and its destructiveness is severe.
文摘Light screen velocity measuring method with unique advantages has been widely used in the velocity measurement of various moving bodies.For large air resistance and friction force which the big moving bodies are subjected to during the light screen velocity measuring,the principle of velocity correction was proposed and a velocity correction equation was derived.A light screen velocity measuring method was used to measure the velocity of big moving bodies which have complex velocity attenuation,and the better results were gained in practical tests.The measuring uncertainty after the velocity correction was calculated.
