We propose a new scripting model for rapid and easier development of packet processing using shell scripts. In this paper we present EtherPIPE, a character network I/O device, that allows the programmer to access netw...We propose a new scripting model for rapid and easier development of packet processing using shell scripts. In this paper we present EtherPIPE, a character network I/O device, that allows the programmer to access network traffic data as a file through UNIX commands. By setting a UNIX pipe "r' from or to EtherP1PE's output or input with UNIX commands, packets can be easily processed, executing functions such as packet filtering, packet capturing, generating arbitrary packets, and rewriting header information. In order to prove the utilities of our model, we have developed FPGA-based EtherPIPE adapter using a commodity FPGA card and a character device driver featuring new offloading functions. With our prototype implementation, packet scripting works at 1Gbps wire-speed, receiving packets with precise hardware timestamps. This paper argues for use cases of the EtherPIPE, and discusses enhanced formats of character devices for easier network scripting.)展开更多
Mantle xenoliths brought up by Cenozoic volcanic rocks onto the earth’s surface may provide direct information about the upper mantle beneath the volcanic region. This paper presents the study on mantle xenoliths col...Mantle xenoliths brought up by Cenozoic volcanic rocks onto the earth’s surface may provide direct information about the upper mantle beneath the volcanic region. This paper presents the study on mantle xenoliths collected from Haoti village, Dangchang County, Gansu Province, western China. The main purpose of the study is to gain an insight into the thermal structure and rheology of the upper mantle beneath the region. The results show that the upper mantle of the region is composed mainly of spinel lherzolite at shallower depth (52~75km), and garnet lherzolite at greater depth (greater than 75km), instead of harzburgite and dunite as proposed by some previous studies. The upper mantle geotherm derived from the equilibrium temperatures and pressures of xenoliths from the region is lower than that of North China, and is somewhat closer to the Oceanic geotherm. The crust-mantle boundary is determined from the geotherm to be at about 52km, and the Moho seems to be the transition zone of lower crust material with spinel lherzolite. If we take 1280℃ as the temperature of the top of asthenosphere, then the lithosphere-asthenosphere boundary should be at about 120km depth. The differential stress of the upper mantle is determined by using recrystallized grain size piezometry, while the strain rate and equivalent viscosity are determined by using the high temperature flow law of peridotite. The differential stress, strain rate and viscosity profiles constructed on the basis of the obtained values indicate that asthenospheric diapir occurred in this region during the Cenozoic time, resulting in the corresponding thinning of the lithosphere. However, the scale and intensity of the diapir was significantly less than that occurring in the North China region. Moreover, numerous small-scale shear zones with localized deformation might occur in the lithospheric mantle, as evidenced by the extensive occurrence of xenoliths with tabular equigranular texture.展开更多
文摘We propose a new scripting model for rapid and easier development of packet processing using shell scripts. In this paper we present EtherPIPE, a character network I/O device, that allows the programmer to access network traffic data as a file through UNIX commands. By setting a UNIX pipe "r' from or to EtherP1PE's output or input with UNIX commands, packets can be easily processed, executing functions such as packet filtering, packet capturing, generating arbitrary packets, and rewriting header information. In order to prove the utilities of our model, we have developed FPGA-based EtherPIPE adapter using a commodity FPGA card and a character device driver featuring new offloading functions. With our prototype implementation, packet scripting works at 1Gbps wire-speed, receiving packets with precise hardware timestamps. This paper argues for use cases of the EtherPIPE, and discusses enhanced formats of character devices for easier network scripting.)
文摘Mantle xenoliths brought up by Cenozoic volcanic rocks onto the earth’s surface may provide direct information about the upper mantle beneath the volcanic region. This paper presents the study on mantle xenoliths collected from Haoti village, Dangchang County, Gansu Province, western China. The main purpose of the study is to gain an insight into the thermal structure and rheology of the upper mantle beneath the region. The results show that the upper mantle of the region is composed mainly of spinel lherzolite at shallower depth (52~75km), and garnet lherzolite at greater depth (greater than 75km), instead of harzburgite and dunite as proposed by some previous studies. The upper mantle geotherm derived from the equilibrium temperatures and pressures of xenoliths from the region is lower than that of North China, and is somewhat closer to the Oceanic geotherm. The crust-mantle boundary is determined from the geotherm to be at about 52km, and the Moho seems to be the transition zone of lower crust material with spinel lherzolite. If we take 1280℃ as the temperature of the top of asthenosphere, then the lithosphere-asthenosphere boundary should be at about 120km depth. The differential stress of the upper mantle is determined by using recrystallized grain size piezometry, while the strain rate and equivalent viscosity are determined by using the high temperature flow law of peridotite. The differential stress, strain rate and viscosity profiles constructed on the basis of the obtained values indicate that asthenospheric diapir occurred in this region during the Cenozoic time, resulting in the corresponding thinning of the lithosphere. However, the scale and intensity of the diapir was significantly less than that occurring in the North China region. Moreover, numerous small-scale shear zones with localized deformation might occur in the lithospheric mantle, as evidenced by the extensive occurrence of xenoliths with tabular equigranular texture.