Abstract:Our research group reported successful observation of "co-faulting" Earth's magnetic field changes due to piezomagnetic effects caused by earthquake rupturing in 2008 Iwate-Miyagi Nairiku earthquake of M7.2 using geomagnetic observation system with fluxgate magnetometers. This is an important finding; the electromagnetic fields propagate from the sources to the observation site at speed of ca. 3.0 × 10 8 m/s in the crustal materials. Further efforts could lead us to a new system for super-early warning of earthquake detection with the geomagnetic signal. On the other hand, the observed result with the earthquake was suggested that the geomagnetic field change accompanying fault movement, whose sources are the piezomagnetic effects, is very small and short term; therefore development of a high-resolution magnetometer system is very important. To solve this problem, we first developed long-term precise geomagnetic observations using high-temperature-superconductor based superconductingquantum-interference-device (HTS-SQUID) magnetometer system. The HTS-SQUID magnetometer system had never achieved for high-resolution geomagnetic observations in outdoor field. Since March 2012, we have observed the geomagnetic field using a first HTS-SQUID magnetometer at Iwaki observation site (IWK) in Fukushima, Japan. In this study, comparison between the introduced HTS-SQUID magnetometer and conventional flux-gate clarified that the HTS-SQUID magnetometer in our system has higher resolution of magnetic field observation.

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For years, researchers have been studying the relation between earthquakes and geomagnetic field signals using observation results. Following our continuous geomagnetic observation, this report describes geomagnetic signal changes generated by earthquakes and tsunami waves. Results show that detection of their occurrence using geomagnetic field measurement is effective for providing an early alarm system for disaster mitigation. Robust detection requires the robust estimation of a geomagnetic field using multiple observation results. This study introduced a deep neural network (DNN) to estimate geomagnetic fields. Results clarified that the proposed DNN model using data of multiple axes at multiple observation points as input data provides efficient solutions for geomagnetic estimation.

The core-shell nanowire had current leakage problem caused by its structure. We have grown the selective regrown core-shell nanowires where the bottom of core was buried by SiO2 to outcome the current leakage problem.

IntroductionRecent years have seen a growing interest in many-corebased parallel computing with a graphics processing unit (GPU) or with Intel many-integrated core (Intel MIC) accelerators in a broad range of fields including acoustic simulation. The movement toward applying GPU to scientific computing has been ongoing since 2005 [1]. A number of studies have reported the application of GPU [2-4] to largescale and long-time acoustic simulation for finite-difference time-domain (FDTD) methods [5][6][7]. On the other hand, the first generation of Intel MIC architecture is newer than GPU because it was only released in 2013. Therefore, fewer studies applying Intel MIC to FDTD methods have been reported [8]; hence, the performance of this accelerator is not known. An Intel MIC accelerator has higher availability than a GPU because its programming model shares many similarities with regular CPUs, which means that Intel MIC can be utilized by regular OpenMP parallelization code written in C/C++ or Fortran. In contrast, GPUs are programmed through APIs such as OpenCL or CUDA (for the NVIDIA GPU).Therefore, in this study, we evaluate the performance of three kinds of acoustic FDTD schemes on the Intel MIC architecture. In addition, we perform software optimizations known in the field of high-performance computing (HPC) [9] to reveal the attainable performance of the Intel MIC architecture. The acoustic FDTD schemes we examined are the standard FDTD(2,2) [10], FDTD(2,4) [11], and WE (Wave Equation) -FDTD(2,2) [3,12] schemes.The purpose of this study is to evaluate the performance of acoustic FDTD schemes on the Intel MIC architecture and to reveal the attainable performance by performing software optimizations.