資料7-HJapanese URSI Commission H (Waves in Plasmas)
Activity Report
November 2013 - February 2014[1] Status of projects related with plasma wave observation
NICT Science CloudNICT Science Cloud has been developed for space plasma studies. We have begun todevelop a Web application for plasma wave data and other satellite observation
data, which is named “STARS touch” (see Figure). This Web application is based ona technique of asynchronous data transfer of graphic files for several types of dataplots. The cloud system create a huge number of data plots with various time scale(e.g., from few minutes to few years) for each data-set. Users can preview
time-dependent observation data of such multi-time scale plots with easy
operations (tap, pinch, drag, flick…). There are 250,000 graphic files for each panel(data) on this application for GEOTAIL satellite. We have a plan to open this Web
site by May 2014.

(An example is shown in the next page.)[2] Recent Meetings
1. COSPAR Symposium on “Planetary Systems of our Sun and other Stars, and theFuture of Space Astronomy”, Bangkok, Thailand, November 11-15, 2013.
2. International CAWSES (Climate and Weather of the Sun-Earth System)-IISymposium, Nagoya, Japan, November 18-22, 2013.
3. 6th VERSIM (VLF/ELF Remote Sensing of the Ionosphere and Magnetosphere)
workshop 2014, 20-23 January 2014, University of Otago, Dunedin, New Zealand.

[3] Future Meetings
1.

Japan Geoscience Union Meeting 2014, Yokohama, Japan, 28 April – 2 May, 2014.

2.

ISRSSP 2014 (Fourth International Symposium on Radio Systems and SpacePlasma) , Luxembourg, 26-27, June, 2014.

3.

AOGS 2014, Sapporo, Japan, 28 July – 1 August, 2014.

4.

The 40th COSPAR Scientific Assembly, Moscow, Russia, 2-10 August, 2014.

5.

The 31st URSI GASS, Beijin, China, 16-23 August, 2014.

6.

AGU Chapman Conference on "Low Frequency Waves in Space Plasmas", Jeju,
Korea, 31 August - 5 September, 2014.

7.

Geospace revisited: a Cluster / MAARBLE / Van Allen Probes Conference, Rhodes,
Greece, 15-20 September, 2014316

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資料7-H[4] Recently Published Papers (November 2013 – February 2014)
1.

M.

Ozaki,S.

Yagitani,H.

Kojima,K.

Takahashi,andA.

Kitagawa,Current-sensitive CMOS preamplifier for investigating space plasma waves bymagnetic search coils, vol.14, no.2, Feb. 2014.
In order to considerably reduce circuit resources (mass, volume, and power) for
the analog front ends of plasma wave measurement systems, a current-sensitive
preamplifier for magnetic search coils (MSCs) is designed with standard 0.25-μm
complementary metal-oxide-semiconductor (CMOS) technology. Since the input
noise current determines the output noise levels around the resonant frequencyof an MSC, a CMOS preamplifier operating with low noise current is suitable
when combined with an MSC instead of using bipolar junction transistors. A
prototype of the CMOS preamplifier was fabricated on a 1.9×3.3-mm2-silicon
chip. The noise equivalent magnetic induction of the CMOS preamplifier
combined with a 100-mm-long MSC is 3.5 pT/Hz1/2 at 10 Hz and 30 fT/Hz1/2 at 2
kHz with a power consumption of 4.6 mW for a 3.3-V supply.
2.

Murata, K. T., Watanabe, H., Kasahara, Y., Yagi, D., Kasai, Y., Ishii, S., Yamamoto,K., Kimura, E., Tanaka, M., Tatebe, O., Ukawa, K., Muranaga, K., Suzuki, Y. andKojima, H., New techniques of high-speed data processing for spacecraft
observation data via NICT Science Cloud, IEICE-SANE2013-94, IEICE-113, No.
335, pp. 133-138, 2013.
A variety of satellite missions, Earth observations and environments, Space
physics and Astrophysics and Commercial uses, are carried out every year. Mostof the satellites yield a large-scale data, and high-performance data processing
technologies are expected. We have been developing a cloud system (the NICTScience Cloud) for big data analyses of Earth and Space observations via
spacecraft. In the present study we propose a new technique to process large-scaledata with paying attention to the fact that high-speed I/O (data file read andwrite) is important compared with data processing itself. We also adopt a taskscheduler, the Pwrake, for easy management of parallel data processing. Using along-time scientific satellite observation data (GEOTAIL satellite), we examine
performance of the system on the NICT Science Cloud. We successfully archivehigh-speed data processing more than 100 times faster than those on traditional318

資料7-Hdata processing environments. Since the design of the present system is forversatile use, we also discuss how to apply for other satellite missions such as
GOSAT satellite, KAGUYA satellite and ISOSIM-L (a radar simulator).
3.

Murata, K. T., Watanabe, H., Ukawa, K., Yamamoto, K. and Zettsu, K.,
Solar-Terrestrial Physics (STP) database system designed for Linked Open Dataand Semantic Web based on RSS1.0 and RDF, 2013 Linked Data in PracticeWorkshop, Seoul, Korea, Nov. 2013.
In many research fields, including the Solar-Terrestrial Physics (STP), it ispointed out that research environment for circulation and utilization ofobservation data among researchers is insufficient. One of the reasons is that thedata formats of observation data are not common. To archive interdisciplinary
researches, we need to overcome this circulation and utilization problems. Under
such a background, the Solar-Terrestrial data Analysis and Reference System(STARS) has been designed and developed by the authors’ group. The STARS has
its own database that manages meta-data of satellite and ground-based
observation data files. The STARS provides users with cross-over data file searchservices and download services over the Internet. It is noted that retrieving
meta-data from the observation data and registering them to database have been
carried out by hand so far in the STARS. It is hard to deal with a huge amount ofobservation data due to the lack of manpower. We developed an automatic
meta-data collection system for the observation data using the STARS RSS (RDFSite Summary) 1.0. Using the RSS1.0 as a meta-data distribution method, theworkflow from retrieving meta-data to registering them into the database isautomated.

4.

Murata, K. T., Watanabe, H., Zettsu K., Kurosawa, T., Kojima, H., Ukawa, K.,
Kimura, E., Tatebe, O. and Tanaka, M., A Proposal of High-resolution Data
Visualization Synchronized with Semantic Web, SIG-SWO-A1302-01, pp. 1-9, 2013.
The NICT Science Cloud is one of the science clouds proposed for development ofsciences. A variety of science data are collected and stored in the science cloud tobe analyzed interdisciplinary. After the Internet is widely used, new concept andinformation technology haves shown up; semantic web and linked open data
(LOD). These technologies enable information on the Internet machine readable.
In many science fields, it is pointed out that the semantic web will play animportant role for the interdisciplinary research works. However, there have been319

資料7-Hfew ideas to be ever proposed as a methodology or roadmap to theinterdisciplinary science using semantic web. Herein we present a concept ofprofessional knowledge and academic knowledge following collective knowledge
proposed as a Web 2.0. Based on the concept, we design an application forinterdisciplinary science.
5.

S. Y. Li, Y. Omura, B. Lembège, X. H. Deng, H. Kojima, Y. Saito, and S. F. Zhang,Geotail observation of counter directed ESWs associated with the separatrix ofmagnetic reconnection in the near-Earth magnetotail, J. Geophys. Res., 119, doi:
10.1002/2013JA018920, 2014.
A sub-Alfve´nic jet in the tailward outflow region near the separatrix of themagnetic reconnection is observed by Geotail on 9 February 1995. Several
dozens of electrostatic solitary waves/pulses (ESWs) are observed, respectively,on the current sheet-side and the lobe-side of the separatrix. The ESWs on thecurrent sheet-side are of type-B with direction outward (toward to the tailward)
while on the lobe-side they are of type-A directed to X-line. The amplitude ofESWs on the current sheet-side is about 6 times more than those on thelobe-side, suggesting that energies flowing outward from the reconnection
X-line are much larger than those flowing inward. Moreover, observations show,that electron beams associated with ESWs, which are parallel to the ambient
magnetic field, are much stronger on the current sheet-side than on thelobe-side of the separatrix. Furthermore, the direction of the electron beam on
the lobe-side of the separatrix is mainly antiparallel to the ambient magnetic
field and it is mainly parallel on the current sheet-side. Both are consistent
with the propagation of ESWs which is in agreement with the generation
mechanism of ESWs, which is suggested to be related to electron beams.

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