One-day high-fat diet induces inflammation in the nodose ganglion and hypothalamus of mice

宮崎大学博士(医学)2015年度doctoral thesi

Collaborative Research Activities of the Arase and Van Allen Probes

This paper presents the highlights of joint observations of the inner magnetosphere by the Arase spacecraft, the Van Allen Probes spacecraft, and ground-based experiments integrated into spacecraft programs. The concurrent operation of the two missions in 2017–2019 facilitated the separation of the spatial and temporal structures of dynamic phenomena occurring in the inner magnetosphere. Because the orbital inclination angle of Arase is larger than that of Van Allen Probes, Arase collected observations at higher L-shells up to L∼10. After March 2017, similar variations in plasma and waves were detected by Van Allen Probes and Arase. We describe plasma wave observations at longitudinally separated locations in space and geomagnetically-conjugate locations in space and on the ground. The results of instrument intercalibrations between the two missions are also presented. Arase continued its normal operation after the scientific operation of Van Allen Probes completed in October 2019. The combined Van Allen Probes (2012-2019) and Arase (2017-present) observations will cover a full solar cycle. This will be the first comprehensive long-term observation of the inner magnetosphere and radiation belts.journal articl

Classification of Time Series Data Obtained by the Satellite by Using Rule-Based and Machine-Learning Methods

Because of its communication volume constraints, scientific observations by nanosatellites need to reduce downlink data by onboard data preprocessing. Therefore, we tried to classify time series data of the geomagnetic field obtained by the SWARM satellite to determine the most appropriate method for onboard classification of a phenomenon in the geomagnetic field. The classifications have been executed using rule-based, K-means, and combined CNN methods. The experimental results demonstrated the effectiveness of the machine-learning model with LSTM networks.The 2023 International Conference on Artificial Life and Robotics (ICAROB 2023), February 9-12, 2023, on line, Oita, Japanconference pape

さいたま教育コラボレーション構想の在り方

textapplication/pdfdepartmental bulletin pape

On-Orbit Magnetometer Data Calibration Using Genetic Algorithm and Interchangeability of the Calibration Parameters

Magnetometers are important sensors with applications in the attitude determination and control systems of satellites. CubeSats have certain limitations related to power, mass, and volume. Due to this, CubeSat magnetometers are not separated from other electrical circuits inside the satellite. Thus, it is important to calibrate the magnetometer, simulating operating conditions while the satellite is running before the launch. However, due to the limited facilities, not every CubeSat is able to calibrate its magnetometers properly on the ground. This study focuses on the calibration of on-orbit magnetometer data observed by BIRDS-3 CubeSats with a genetic algorithm. High oscillations in the total magnetic field were found in the on-orbit magnetic field data measured by magnetometers inside BIRDS-3 CubeSats. Nine unknowns, scaling factors, non-orthogonal angles, and offsets are identified with the genetic algorithm. This paper discusses the factors that affect the high oscillations in the measured total magnetic field data. For the calibration, we used magnetic field data similar to those of a model magnetic field, as the deviation is smaller. This paper presents the accuracy of determining unknowns using the genetic algorithm, as well as the interchangeability of the answers with additional orbit data from the same satellite. This method can be used in the future to calibrate magnetometers inside CubeSats before or after launch.journal articl

Classification of Satellite-Obtained Time Series Data: A Comparative Study of Rule-Based and Machine-Learning Approaches

conference pape

Ultra Low Frequency Modulation of Energetic Electron Precipitation in the D-Region Ionosphere in a Magnetically Quiet Time Using OCTAVE Very Low Frequency and Low Frequency (VLF/LF) Observations

There are several studies of energetic electron precipitation (EEP) modulated by ultra low frequency (ULF) during substorms, although there are few in geomagnetically quiet times. At present, it is not clear how often such quiet time EEP occurs and the mechanism involved. In this study, we investigate EEP modulated by ULF (,5 Hz) from Observation of CondiTion of ionized Atmosphere by VLF Experiment (OCTAVE) very low frequency (VLF; 3 kHz to 30 kHz) and low frequency (LF; 30 kHz to 300 kHz) observations in geomagnetically quiet times. The OCTAVE is a worldwide network of VLF/LF signals that we established. The VLF/LF transmitter signals from four transmitters (NLK, NDK, WWVB, and NAA) in the USA were received at Athabasca (ATH; 54.78N, 113.38E, L . 4.3), Canada. There were oscillations in amplitude on the NDK-ATH and NLK-ATH paths with periods of 240 s and 270 s during magnetically quiet times from 11:20 Universal Time (UT) to 11:40 UT on October 9, 2017, respectively. The amplitudes of the VLF/LF variations were 3 dB and 1 dB on the NDKATH and NLK-ATH paths, respectively. Based on the wave–hop method, reflection height varied by ~4.3 km during the VLF/LF oscillations, indicating that the electron density in the D-region ionosphere increased by ~680 cm_3 (110%) at a 91 km height. The H component of ground-based magnetic field data at ATH and low latitudes showed the geomagnetic Pi2 pulsations with a similar period to that in the VLF/LF signals. The main cause of the VLF/LF oscillations could be ULF-modulated EEP due to the lowering of mirror points.journal articl

PCUBE: Probing, controlling, and understanding of radiation belt environments

conference pape

Program management for sustainable university CubeSat programs based on the experience of five generations of CubeSat projects, BIRDS program

BIRDS program is a university CubeSat program whose primary mission is capacity building of non-space faring countries. It has been run by Kyushu Institute of Technology, Japan, where a group of foreign and Japanese students designs, builds, tests and operates CubeSats. The program started in 2015. Roughly every year since 2017, BIRDS program delivered and launched multiple CubeSats from International Space Station. In total, the program generated 17 CubeSats in five generations. The satellites have been designed in a way so that even satellite beginners can go through the satellite system life cycles from the mission definition to the operation in two years, the duration of Master course. Subsequent generations of students overlap in the laboratory so that they can inherit the know-hows and the experience directly in-person. The satellite design has been modified based on the lessons learned in the former generations, especially during the operation phase. After going through the series of developments and operations, the satellite bus has become very mature. Currently, the initiative to open-source the BIRDS bus is also running. The program, rather than project, management aspects of university CubeSat program is discussed.36th Annual Small Satellite Conference, August 6-11, 2022, Logan, Utah, USconference pape

Signatures of Auroral Potential Structure Extending Through the Near‐Equatorial Inner Magnetosphere

journal articl