Spectral model of optical scintillation for terrestrial free-space optical communication link design

Kyung-Hwan Kim, Takeshi Higashino, Katsutoshi Tsukamoto, Shozo Komaki, Kamugisha Kazaura and Mitsuji Matsumoto, "Spectral model of optical scintillation for terrestrial free-space optical communication link design", Opt. Eng. 50, 035005 (Mar 25, 2011

Studies on characterizing the transmission of RF signals over a turbulent FSO link

This paper was published in Optics Express and is made available as an electronic reprint with the permission of OSA. The paper can be found at the following URL on the OSA website: http://dx.doi.org/10.1364/OE.17.007731 Systematic or multiple reproduction or distribution to multiple locations via electronic or other means is prohibited and is subject to penalties under law

The K computer Operations: Experiences and Statistics

AbstractThe K computer, released on September 29, 2012, is a large-scale parallel supercomputer system consisting of 82,944 compute nodes. We have been able to resolve a significant number of operation issues since its release. Some system software components have been fixed and improved to obtain higher stability and utilization. We achieved 94% service availability because of a low hardware failure rate and approximately 80% node utilization by careful adjustment of operation parameters. We found that the K computer is an extremely stable and high utilization system