Hirotsugu Kojima

Learn More
STUDY DESIGN Posterolateral lumbar transverse process fusion was completed using the cultured bone marrow cells in type I collagen gel and porous hydroxyapatite. OBJECTIVE To compare the efficacy of cultured bone marrow cells with that of bone morphogenetic protein (BMP) as a graft alternative to autologous bone for posterolateral spine fusion. SUMMARY(More)
SUMMARY A sensor network consisting of a number of palm-sized nodes with small electric and magnetic sensors has been proposed to monitor local electromagnetic activities in space plasmas. In the present study, a compact loop antenna system is designed and fabricated for use in sensor nodes that can capture magnetic vector fields from ELF to MF frequencies.(More)
Most visible matter in the Universe exists as plasma. How this plasma is heated, and especially how the initial non-equilibrium plasma distributions relax to thermal equilibrium (as predicted by Maxwell-Boltzman statistics), is a fundamental question in studies of astrophysical and laboratory plasmas. Astrophysical plasmas are often so tenuous that binary(More)
—A software wave receiver was aboard the SS-520-2 rocket as a part of the plasma wave analyzer and successfully accomplished waveform observations and spectral observations. In the present paper, we describe the specifications and roles of the software wave receiver on the SS-520-2 rocket experiment. This receiver consists of a waveform receiver using(More)
Background: Multipoint observations of plasma waves are essential for separating spatial and temporal variations of a plasma turbulence. Miniaturization and high environmental (temperature and radiation) robustness are key requirements for scientific instrument design toward a sensor network consisting of palm-sized probes. With increasing these demands, a(More)
  • 1