Search

Your search keyword '"Iida, Yusuke"' showing total 162 results
Start Over Author "Iida, Yusuke"
162 results on '"Iida, Yusuke"'

1. Compression Method for Solar Polarization Spectra Collected from Hinode SOT/SP Observations

Author

Batmunkh, Jargalmaa, Iida, Yusuke, Oba, Takayoshi, and Iijima, Haruhisa

Subjects
Computer Science - Machine Learning, Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - Solar and Stellar Astrophysics
Abstract

The complex structure and extensive details of solar spectral data, combined with a recent surge in volume, present significant processing challenges. To address this, we propose a deep learning-based compression technique using deep autoencoder (DAE) and 1D-convolutional autoencoder (CAE) models developed with Hinode SOT/SP data. We focused on compressing Stokes I and V polarization spectra from the quiet Sun, as well as from active regions, providing a novel insight into comprehensive spectral analysis by incorporating spectra from extreme magnetic fields. The results indicate that the CAE model outperforms the DAE model in reconstructing Stokes profiles, demonstrating greater robustness and achieving reconstruction errors around the observational noise level. The proposed method has proven effective in compressing Stokes I and V spectra from both the quiet Sun and active regions, highlighting its potential for impactful applications in solar spectral analysis, such as detection of unusual spectral signals.

Published
2024

3. Successful preventive treatment with cyclosporine in a patient with relapsed/refractory immune-mediated thrombotic thrombocytopenic purpura: a case report and review of the literature

Author

Uchino, Kaori, Sakai, Kazuya, Shinohara, Saki, Matsuhisa, Akifumi, Iida, Yusuke, Nakano, Yuta, Matsumura, Saori, Kanasugi, Jo, Takasugi, Soichi, Nakamura, Ayano, Horio, Tomohiro, Murakami, Satsuki, Mizuno, Shohei, Yamamoto, Hidesuke, Hanamura, Ichiro, Matsumoto, Masanori, and Takami, Akiyoshi

Published
2022
Full Text
View/download PDF

5. Primary Bladder Lymphoma with Extravesical Extension: A Case Report and Literature Review on Prognosis and Clinical Characteristics.

Author

Seki, Hideshige, Mizuno, Shohei, Saigusa, Sakura, Sugita, Yukie, Iida, Yusuke, Shinohara, Saki, Uchino, Kaori, Horio, Tomohiro, Hanamura, Ichiro, and Takami, Akiyoshi

Subjects
DIFFUSE large B-cell lymphomas, MUCOSA-associated lymphoid tissue lymphoma, LITERATURE reviews, PROGNOSIS, ADIPOSE tissues, URINARY tract infections
Abstract

Background: Primary bladder lymphoma is generally regarded as having a favorable prognosis due to the predominance of low-grade lymphomas confined to the bladder. However, our investigation reveals that cases with extravesical extension, predominantly involving diffuse large B-cell lymphoma (DLBCL), exhibit a distinct clinical course with varied prognostic outcomes. Methods: In this report, we present and analyzed the clinical features and outcomes of 47 patients with primary bladder lymphoma with extravesical extension, including the case that we experienced. Results: An 77-year-old man who experienced fever, anorexia, and general malaise was referred to our hospital. Initial laboratory tests indicated severe renal failure, pyuria, and Escherichia coli bacteremia, accompanied by diffuse thickening of the bladder walls and increased attenuation in the surrounding adipose tissues. Initially misdiagnosed with a severe urinary tract infection leading to sepsis, the patient was treated with antibiotics and hemodialysis. Upon readmission due to abdominal pressure, imaging identified an intra-abdominal mass connected to the bladder wall. A bladder biopsy was performed, resulting in the diagnosis of primary bladder DLBCL with perivesical extension, classified as germinal center B-cell type. Taking inspiration from this case, the review of 46 patients was implemented. As a result, we resolved that primary bladder lymphoma often includes indolent types like Mucosa-associated lymphoid tissue lymphoma, but cases with extravesical expansion are predominantly DLBCL. Conclusions: This case emphasizes the diagnostic complexities of distinguishing primary bladder lymphoma from urinary tract infections and underscores the prognostic implications of extravesical extension. Our comprehensive review of the literature on primary bladder lymphomas with extravesical involvement highlights the clinical characteristics, therapeutic challenges, and need for heightened diagnostic vigilance and tailored treatment strategies for this subset of patients. [ABSTRACT FROM AUTHOR]

Published
2024
Full Text
View/download PDF

6. Comparison between Hinode/SOT and SDO/HMI, AIA Data for the Study of the Solar Flare Trigger Process

Author

Bamba, Yumi, Kusano, Kanya, Imada, Shinsuke, and Iida, Yusuke

Subjects
Astrophysics - Solar and Stellar Astrophysics
Abstract

To elucidate the flare trigger mechanism, we have analyzed several flare events which were observed by Hinode/Solar Optical Telescope (SOT), in our previous study. Because of the limitation of SOT field of view, however, only four events in the Hinode data sets have been utilizable. Therefore, increasing the number of events is required for evaluating the flare trigger models. We investigated the applicability of data obtained by the Solar Dynamics Observatory (SDO) to increase the data sample for a statistical analysis of the flare trigger process. SDO regularly observes the full disk of the sun and all flares although its spatial resolution is lower than that of Hinode. We investigated the M6.6 flare which occurred on 13 February 2011 and compared the analyzed data of SDO with the results of our previous study using Hinode/SOT data. Filter and vector magnetograms obtained by the Helioseismic and Magnetic Imager (HMI) and filtergrams from the Atmospheric Imaging Assembly (AIA) 1600A were employed. From the comparison of small-scale magnetic configurations and chromospheric emission prior to the flare onset, we confirmed that the trigger region is detectable with the SDO data. We also measured the magnetic shear angles of the active region and the azimuth and strength of the flare-trigger field. The results were consistent with our previous study. We concluded that statistical studies of the flare trigger process are feasible with SDO as well as Hinode data. We also investigated the temporal evolution of the magnetic field before the flare onset with SDO.

Published
2014
Full Text
View/download PDF

7. Magnetic Systems Triggering the M6.6-class Solar Flare in NOAA Active Region 11158

Author

Toriumi, Shin, Iida, Yusuke, Bamba, Yumi, Kusano, Kanya, Imada, Shinsuke, and Inoue, Satoshi

Subjects
Astrophysics - Solar and Stellar Astrophysics
Abstract

We report a detailed event analysis on the M6.6-class flare in the active region (AR) NOAA 11158 on 2011 February 13. AR 11158, which consisted of two major emerging bipoles, showed prominent activities including one X- and several M-class flares. In order to investigate the magnetic structures related to the M6.6 event, particularly the formation process of a flare-triggering magnetic region, we analyzed multiple spacecraft observations and numerical results of a flare simulation. We observed that, in the center of this quadrupolar AR, a highly sheared polarity inversion line (PIL) was formed through proper motions of the major magnetic elements, which built a sheared coronal arcade lying over the PIL. The observations lend support to the interpretation that the target flare was triggered by a localized magnetic region that had an intrusive structure, namely a positive polarity penetrating into a negative counterpart. The geometrical relationship between the sheared coronal arcade and the triggering region was consistent with the theoretical flare model based on the previous numerical study. We found that the formation of the trigger region was due to a continuous accumulation of the small-scale magnetic patches. A few hours before the flare occurrence, the series of emerged/advected patches reconnected with a preexisting fields. Finally, the abrupt flare eruption of the M6.6 event started around 17:30 UT. Our analysis suggests that, in a triggering process of a flare activity, all magnetic systems of multiple scales, not only the entire AR evolution but also the fine magnetic elements, are altogether involved., Comment: 34 pages, 8 figures, accepted for publication in ApJ. A high-quality version can be found at http://www-space.eps.s.u-tokyo.ac.jp/~toriumi/toriumi2013apj.pdf

Published
2013
Full Text
View/download PDF

10. The effects of magnetic fields on rolling contact fatigue wear

Author

Iida, Yusuke, Stolarski, T. A., and Sato, K.

Subjects
621.89
Abstract

The thesis describes the effects of the magnetic field in rolling contact tests of steel by using a two-disc machine and the investigation of its mechanism from contact stress analysis by using FEM and the agnetisation of a ferromagnetic substance. In the tests, two contact kinematic conditions, that is pure rolling and 10% rolling with sliding together with 1.1 and OAT [Tesla] of horizontal static magnetic fields created by permanent magnets were pplied. The results of optical and scanning electron microscopy observations show that finer wear particles and smoother worn surfaces are produced in the presence of the magnetic field. For the generation of the finer wear particles, it is considered necessary that the subsurface crack initiation point is moved towards the surface due to the magnetic field. Wear amounts of the discs are lowered III the magnetic fields under the pure rolling conditions. However, at 100/0 rolling with sliding, the wear amounts are increased in the magnetic fields even though finer particles and smoother surfaces are observed. Both tendencies are unified by calculating the number of cycles required to generate wear particles, which are reduced due to the magnetic field's presence. For these mechanisms, it is considered that domain walls near the contact region are caught by dislocations when the specimen is agnetised and part of the energy for magnetisation activates the dislocation movement resulting in crack initiation.

Published
2007

16. Analysis of Customer Preference through Unforced Natural Passive Observation

Author

Tajima, Terumasa, Iida, Yusuke, Kato, Toshikazu, Hutchison, David, editor, Kanade, Takeo, editor, Kittler, Josef, editor, Kleinberg, Jon M., editor, Mattern, Friedemann, editor, Mitchell, John C., editor, Naor, Moni, editor, Nierstrasz, Oscar, editor, Pandu Rangan, C., editor, Steffen, Bernhard, editor, Sudan, Madhu, editor, Terzopoulos, Demetri, editor, Tygar, Doug, editor, Vardi, Moshe Y., editor, Weikum, Gerhard, editor, and Kurosu, Masaaki, editor

Published
2013
Full Text
View/download PDF

17. Smart Store Understanding Consumer’s Preference through Behavior Logs

Author

Ogino, Akihiro, Kobayashi, Taketo, Iida, Yusuke, Kato, Toshikazu, Hutchison, David, Series editor, Kanade, Takeo, Series editor, Kittler, Josef, Series editor, Kleinberg, Jon M., Series editor, Mattern, Friedemann, Series editor, Mitchell, John C., Series editor, Naor, Moni, Series editor, Nierstrasz, Oscar, Series editor, Pandu Rangan, C., Series editor, Steffen, Bernhard, Series editor, Sudan, Madhu, Series editor, Terzopoulos, Demetri, Series editor, Tygar, Doug, Series editor, Vardi, Moshe Y., Series editor, Weikum, Gerhard, Series editor, and Rau, P. L. Patrick, editor

Published
2011
Full Text
View/download PDF

21. Tracking of magnetic flux concentrations over a five-day observation, and an insight into surface magnetic flux transport

Author

Iida Yusuke

Subjects
Sun, Magnetic field, Photosphere, Surface, Solar cycle, Meteorology. Climatology, QC851-999
Abstract

The solar dynamo problem is the question of how the cyclic variation in the solar magnetic field is maintained. One of the important processes is the transport of magnetic flux by surface convection. To reveal this process, the dependence of the squared displacement of magnetic flux concentrations on the elapsed time is investigated in this paper via a feature-recognition technique and a continual five-day magnetogram. This represents the longest time scale over which a satellite observation has ever been performed for this problem. The dependence is found to follow a power law and differ significantly from that of diffusion transport. Furthermore, there is a change in the behavior at a spatial scale of 103.8 km. A super-diffusion behavior with an index of 1.4 is found at smaller scales, while changing to a sub-diffusion behavior with an index of 0.6 on larger ones. We interpret this difference in the transport regime as coming from the network-flow pattern.

Published
2016
Full Text
View/download PDF

27. Solar-C(EUVST)における科学運用とデータ処理

Author

ほか, Solar-C (EUVST)プリプロ準備チーム, TORIUMI, Shin, SHIMIZU, Toshifumi, MATSUZAKI, Keiichi, TEI, Akiko, IMADA, Shinsuke, KUSANO, Kanya, SUEMATSU, Yoshinori, HARA, Hirohisa, KATSUKAWA, Yukio, KUBO, Masahito, WATANABE, Tetsuya, ICHIMOTO, Kiyoshi, ASAI, Ayumu, NAGATA, Shinichi, KAWATE, Tomoko, YOKOYAMA, Takaaki, WATANABE, Kyoko, and IIDA, Yusuke

Abstract

第21回宇宙科学シンポジウム (2021年1月6日-7日. オンライン開催), 21st Space Science Symposium (January 6-7, 2021. Online Meeting), 著者人数: 18名ほか, 資料番号: SA6000163040, レポート番号: g01-08

Published
2021

28. Solar-C(EUVST)の進捗状況

Author

ほかSolar, C(EUVST)プリプロ準備チーム, SHIMIZU, Toshifumi, TORIUMI, Shin, TEI, Akiko, BINGO, Hiroki, HARA, Hirohisa, SUEMATSU, Yoshinori, KATSUKAWA, Yukio, KUBO, Masahito, ISHIKAWA, Ryoko, TSUZUKI, Noriaki, NODOMI, Yoshifumi, SHINODA, Kazuya, WATANABE, Tetsuya, IMADA, Shinsuke, KUSANO, Kanya, MASUDA, Satoshi, KAWATE, Tomoko, YOKOYAMA, Takaaki, HASEGAWA, Takahiro, ICHIMOTO, Kiyoshi, NAGATA, Shinichi, ASAI, Ayumu, WATANABE, Kyoko, IIDA, Yusuke, MINESUGI, Kenji, GOTO, Ken, TACHIKAWA, Sumitaka, OGAWA, Hiroyuki, MATSUZAKI, Keiichi, FUKUDA, Seisuke, ITO, Takuhiro, OKADA, Norio, NAKATSUBO, Shunichi, NISHINO, Tetsuo, YAMAZAKI, Atsushi, MURAKAMI, Go, HASHIMOTO, Tatsuaki, SAKAI, Shinichiro, OBARA, Shingo, KIMOTO, Yugo, SHIMAZAKI, Kazunori, YAMANAKA, Riyo, MIYAZAKI, Eiji, and TSUNO, Katsuhiko

Abstract

第21回宇宙科学シンポジウム (2021年1月6日-7日. オンライン開催), 21st Space Science Symposium (January 6-7, 2021. Online Meeting), 著者人数: 44名ほか, 資料番号: SA6000163022, レポート番号: S5-004

Published
2021

32. ひので衛星で得られたコロナ質量放出・シグモイド構造イベントリストの公開

Author

LEE, Kyoung-Sun, KAWATE, Tomoko, KAWABATA, Yusuke, IIDA, Yusuke, DOI, Takafumi, HASEGAWA, Takahiro, BAMBA, Yumi, AKIYAMA, Sachiko, YASHIRO, Seiji, and SHIMIZU, Toshifumi

Abstract

2019(令和元)年度宇宙科学情報解析シンポジウム(2020年2月14日. 宇宙航空研究開発機構宇宙科学研究所(JAXA)(ISAS)), 相模原市, 神奈川県, Space Science Informatics Symposium FY2019(February 14, 2020. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency(JAXA)(ISAS)), Sagamihara, Kanagawa Japan, 資料番号: SA6000150006

Published
2020

33. Rotating Mechanism for Space Telescopes: Long Lifetime Performance in Vacuum Environment

Author

Lee, Kyoung-Sun, QuinteroNoda, Carlos, Shimizu, Toshifumi, Watanabe, Kyoko, Kawabata, Yusuke, Oba, Takayoshi, Iida, Yusuke, Kano, Ryuichi, Ishikawa, Shinnosuke, Doi, Takafumi, and Hasegawa, Takahiro

Subjects
reliability, space-borne telescopes, ball bearing mechanism, rotation, space observations
Abstract

フィルターホイールや連続回転機構などの回転駆動機構は, 宇宙科学研究において様々な新しい科学計測を可能にして, 豊富な観測機能や可能性が科学装置に付け加わる. 連続回転機構は, 宇宙望遠鏡の光路中におかれた波長板を回転させ, 観測する光線に含まれる偏光を精密に計測することが可能になる. 太陽光線中の偏光を計測することで, 太陽大気中の磁場を詳細に診断することができる. 次世代太陽観測ミッション計画SOLAR-Cで検討された太陽光学磁場診断望遠鏡(SUVIT)など, 宇宙望遠鏡で用いられる連続回転機構にとって, 非常に多数回数(10(exp 7)-10(exp 8)回転以上)を確実に行うことができる高い信頼性は不可欠である. 我々は, 連続回転駆動機構の試作品を開発した. 試作品は中空の大きな開口を持ち, 中空の大口径薄肉軸受と中空DCブラシレスモータを使用している. 真空環境下での寿命試験を通じて, 軸受周りの設計に改良を加える取組みの結果, 10(exp 8)回以上の回転を実現した. 試験に用いた試作品は現在国際観測ロケットCLASPとCLASP2及び国際大気球観測SUNRISE-3の精密偏光計測で活用されている., Rotation devices, such as filter wheels and continuous rotating mechanism, enable us to perform new kinds of scientific measurements valuable in space science and provide a rich number of observing functions and capabilities to scientific instruments. The concept of a continuous rotating mechanism is based on the rotation of a waveplate placed in the light path of telescopes for accurate measurements of the degree of polarization of the observed light. This degree of polarization can be used to diagnose the thermal and magnetic properties of the solar atmosphere. High reliability performance with a large number of operations (higher than 10(exp 7)-10(exp 8) rotations) is required for the continuous rotation mechanism used in space-borne telescopes, such as the Solar UV-Visible-near Infrared Telescope (SUVIT) for the next generation solar observing mission (SOLAR-C). In this regard, we completed the development of prototype continuous rotation mechanisms which have a large optical aperture with a pair of large-size thin section ball bearings and a hollow DC blushless motor. We achieved a number of operations higher than 10(exp 8) times by performing lifetime tests in a vacuum environment while upgrading the design of the bearings for improving their performance. These newly developed rotating mechanisms are employed in various solar missions such as the sounding rocket experiment CLASP and CLASP-2, and balloon-borne experiment SUNRISE-3., 形態: カラー図版あり, Physical characteristics: Original contains color illustrations, 資料番号: AA1830007000, レポート番号: JAXA-RR-18-003

Published
2018

37. Simulation Study on Novel GaN‐Based n−p−n Heterojunction Bipolar Transistors with a Quaternary AlGaInN Emitter and a Two‐Dimensionally Conductive Base.

Author

Mase, Akira, Nikai, Yutaka, Iida, Yusuke, Egawa, Takashi, and Miyoshi, Makoto

Subjects
HETEROJUNCTION bipolar transistors, TRANSISTORS, CARRIER density, GENERATING functions, QUANTUM wells
Abstract

Herein, a simulation study on novel GaN‐based n−p−n heterojunction bipolar transistors (HBTs) with a quaternary n‐AlGaInN emitter and a thin GaInN quantum well (QW) layer inserted in its p‐GaN base is reported. The idea of the quaternary AlGaInN emitter facilitates the design and independent growth of the energy bandgaps and lattice strain. In addition, the p‐GaN base inserted with the thin GaInN QW is expected to be effective in enhancing its lateral conduction via 2D hole gases (2DHGs). The simulation results indicate that the designed GaInN QW definitely functions to generate and transport the 2DHGs and ultimately contributes to the improvement of the device performance. In other words, the lateral resistivity of the p‐GaN base is reduced from 1.8 × 10−1 to 7.0 × 10−2 Ω cm with the use of the GaInN QW insertion layer. Further, the simulation study focusing on the lateral distance between the n‐emitter and p‐base electrodes exhibits stable device characteristics for the HBT with the GaInN QW insertion layer compared with the conventional HBT structure. Dynamic analysis of the carrier concentration distribution indicates that the QW functions as a low‐resistance current path and it has the effect of avoiding the punch‐through phenomenon. [ABSTRACT FROM AUTHOR]

Published
2022
Full Text
View/download PDF

39. Summary on reliability performance of rotating mechanism developed for space telescopes

Author

Lee, Kyoung-Sun, Quintero, Noda Carlos, Shimizu, Toshifumi, Watanabe, Kyoko, Kawabata, Yusuke, Oba, Takayoshi, Iida, Yusuke, Kanoh, Ryuichi, Ishikawa, Shin-nosuke, Doi, Takafumi, and Hasegawa, Takahiro

Abstract

第18回宇宙科学シンポジウム (2018年1月9日-10日. 宇宙航空研究開発機構宇宙科学研究所(JAXA)(ISAS)相模原キャンパス), 相模原市, 神奈川県, 18th Space Science Symposium (January 9-10, 2018. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency(JAXA)(ISAS)Sagamihara Campus), Sagamihara, Kanagawa Japan, 著者人数: 11名, 資料番号: SA6000118162, レポート番号: P-129

Published
2018

40. 太陽光球大気における3次元対流速度場

Author

Oba, Takayoshi, Iida, Yusuke, and Shimizu, Toshifumi

Abstract

第18回宇宙科学シンポジウム (2018年1月9日-10日. 宇宙航空研究開発機構宇宙科学研究所(JAXA)(ISAS)相模原キャンパス), 相模原市, 神奈川県, 18th Space Science Symposium (January 9-10, 2018. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency(JAXA)(ISAS)Sagamihara Campus), Sagamihara, Kanagawa Japan, 資料番号: SA6000118038, レポート番号: P-003

Published
2018

41. Measurement of the Lower Hybrid Wave Using RF Magnetic Probes on the TST-2 Spherical Tokamak

Author

KO, Yongtae, primary, TSUJII, Naoto, additional, YAJIMA, Satoru, additional, TAKASE, Yuichi, additional, EJIRI, Akira, additional, WATANABE, Osamu, additional, YAMAZAKI, Hibiki, additional, MOELLER, Charles P., additional, YOSHIMURA, Yasuo, additional, YOSHIDA, Yusuke, additional, IIDA, Yusuke, additional, IWASAKI, Kotaro, additional, KAWAMATA, Yuya, additional, SAKAMOTO, Sho, additional, AOI, Yuki, additional, OISHI, Teruki, additional, MATSUZAKI, Kyohei, additional, and RICE, James, additional

Published
2019
Full Text
View/download PDF

45. Development of Linear Motion Mechanism for High-Precision Space Telescopes: Performance Assessment with a Large Number of Operations in Vacuum Environments

Author

Lee, Kyoung-Sun, Oba, Takayoshi, Nishizuka, Naoto, Watanabe, Kyoko, Iida, Yusuke, Tajima, Takao, Nakayama, Satoshi, and Shimizu, Toshifumi

Subjects
reliability, space-borne telescopes, linear motion mechanism, Solar-C
Abstract

高精度の天文観測を行う高解像度の大口径宇宙望遠鏡にとって, 焦点面検出器上の観測像に最適なピントを合わせるための直動機構が必須である. 現在検討中の次世代太陽観測衛星（Solar-C）に搭載される光学磁場診断望遠鏡（SUVIT）についても, 各焦点面観測装置に焦点調節機構が必要である. この望遠鏡（口径～1.4m）が0.1 秒角もしくはそれ以上の解像度を達成できるために, 我々は焦点調節機構（FMA）と呼ばれる直動機構の国内開発研究の新規化を進めてきた. FMA は望遠鏡の性能実現において極めて重要な部品の一つであり, 長寿命・高信頼性が求められる. 望遠鏡のシステム設計に対しても, ミッション開発の初期段階において長寿命性能の検証を行い, FMA 開発の目処を立てておくことは不可欠である. そこで, FMA の試作品を開発し, 真空環境下にて長寿命性能の検証を行った. 2 種類の駆動レンジに対して前後への往復運動を10 万回以上問題なく行えることを確認した. この達成した駆動回数は, ミッション期間中に軌道上で想定される駆動回数の5 倍以上に相当する., Large-aperture space telescopes for high-precision astronomical measurements with high spatial resolution performance may require a linear motion mechanism for optimizing the focus of images on their focal plane detectors. The solar UV-Visible-near IR telescope (SUVIT) for the next generation solar observing mission (Solar-C) currently under feasibility study requires focus adjusting mechanisms for each of its focal plane instruments. For achieving 0.1 arcsec or better spatial resolution with about 1.4 m diameter aperture of the telescope, we have been newly developing a linear motion mechanism, called the focus mechanism assembly (FMA). High reliability performance with a large number of operations is required for the FMA as one of the mission critical components in the telescope, and the verification of the performance at the early phase of the mission development is essential for defining the telescope system design. With developing a proto-type mechanism, we tested the performance under vacuum environments and confirmed over 1x105 cycles of the back-and-forth motion in two different strokes. The confirmed number of operations is at least 5 times larger than the number of operations assumed on orbit., 形態: カラー図版あり, Physical characteristics: Original contains color illustrations, 資料番号: AA1530021000, レポート番号: JAXA-RR-14-006

Published
2015

46. High Accuracy Measurements of the Outgassing Properties of a Rotating Mechanism for the Space Telescope

Author

Lee, Kyoung-Sun, Watanabe, Kyoko, Shimizu, Toshifumi, Iida, Yusuke, and Oba, Takayoshi

Subjects
Low outgassing lubricant, Space-borne telescopes, Contamination control
Abstract

次期太陽観測衛星計画「SOLAR-C」用光学磁場診断望遠鏡（SUVIT）への搭載を目指して，望遠鏡光路中で常時回転する回転駆動機構の要素開発を行っている。コンタミ管理レベルの厳しい望遠鏡内部で使用できる機器を実現するために，回転駆動機構には各種アウトガス対策を施している．現在、回転駆動機構試作品を真空環境下で連続駆動させて、寿命性能を評価する試験を行っている。この真空試験おいて、回転駆動中の機構から放出されるアウトガス量およびその変化を高精度に計測するために、新しいTQCM治具を開発し、定期的にアウトガス測定を行ってきた。1年以上にわたるアウトガス計測から、回転する機構からの発生アウトガス量に目立った経年変化はなく、低アウトガスレートが維持されていることを確認した。この計測から、本研究で開発中の機構は、コンタミ管理が厳しい望遠鏡内部で使用できる目処が付いた。, We have been developing a rotating mechanism to rotate a waveplate in the light beam from a space solar telescope to be flown onboard the next solar satellite mission, Solar-C. Because the performance of this telescope is very sensitive to contaminants on the optical surfaces, the rotating mechanism shall have a low outgassing performance. We are currently evaluating its life-duration performance by operating it in a small vacuum chamber to ensure the number of operations required in the mission life. During this test, we also measured the outgassing rate every month. The data from a run in more than 1 year shows that the outgassing rate from the mechanism is kept low. We confirmed this mechanism could be used under stringent conditions for contaminants., 形態: カラー図版あり, Physical characteristics: Original contains color illustrations, 資料番号: AA1530004000, レポート番号: JAXA-RR-14-008

Published
2015

47. 宇宙望遠鏡用連続回転駆動機構: 真空環境下での長寿命特性

Author

清水, 敏文, 渡邉, 恭子, 川畑, 佑典, 大場, 崇義, 飯田, 佑輔, Lee, Kyoung-Sun, 加納, 龍一, 石川, 真之介, 土井, 崇史, 長谷川, 隆祥, Quintero Noda, Carlos, Shimizu, Toshifumi, Watanabe, Kyoko, Kawabata, Yusuke, Oba, Takayoshi, Iida, Yusuke, Kano, Ryuichi, Ishikawa, Shinnosuke, Doi, Takafumi, Hasegawa, Takahiro, 清水, 敏文, 渡邉, 恭子, 川畑, 佑典, 大場, 崇義, 飯田, 佑輔, Lee, Kyoung-Sun, 加納, 龍一, 石川, 真之介, 土井, 崇史, 長谷川, 隆祥, Quintero Noda, Carlos, Shimizu, Toshifumi, Watanabe, Kyoko, Kawabata, Yusuke, Oba, Takayoshi, Iida, Yusuke, Kano, Ryuichi, Ishikawa, Shinnosuke, Doi, Takafumi, and Hasegawa, Takahiro

Abstract

フィルターホイールや連続回転機構などの回転駆動機構は, 宇宙科学研究において様々な新しい科学計測を可能にして, 豊富な観測機能や可能性が科学装置に付け加わる. 連続回転機構は, 宇宙望遠鏡の光路中におかれた波長板を回転させ, 観測する光線に含まれる偏光を精密に計測することが可能になる. 太陽光線中の偏光を計測することで, 太陽大気中の磁場を詳細に診断することができる. 次世代太陽観測ミッション計画SOLAR-Cで検討された太陽光学磁場診断望遠鏡(SUVIT)など, 宇宙望遠鏡で用いられる連続回転機構にとって, 非常に多数回数(10(exp 7)-10(exp 8)回転以上)を確実に行うことができる高い信頼性は不可欠である. 我々は, 連続回転駆動機構の試作品を開発した. 試作品は中空の大きな開口を持ち, 中空の大口径薄肉軸受と中空DCブラシレスモータを使用している. 真空環境下での寿命試験を通じて, 軸受周りの設計に改良を加える取組みの結果, 10(exp 8)回以上の回転を実現した. 試験に用いた試作品は現在国際観測ロケットCLASPとCLASP2及び国際大気球観測SUNRISE-3の精密偏光計測で活用されている., Rotation devices, such as filter wheels and continuous rotating mechanism, enable us to perform new kinds of scientific measurements valuable in space science and provide a rich number of observing functions and capabilities to scientific instruments. The concept of a continuous rotating mechanism is based on the rotation of a waveplate placed in the light path of telescopes for accurate measurements of the degree of polarization of the observed light. This degree of polarization can be used to diagnose the thermal and magnetic properties of the solar atmosphere. High reliability performance with a large number of operations (higher than 10(exp 7)-10(exp 8) rotations) is required for the continuous rotation mechanism used in space-borne telescopes, such as the Solar UV-Visible-near Infrared Telescope (SUVIT) for the next generation solar observing mission (SOLAR-C). In this regard, we completed the development of prototype continuous rotation mechanisms which have a large optical aperture with a pair of large-size thin section ball bearings and a hollow DC blushless motor. We achieved a number of operations higher than 10(exp 8) times by performing lifetime tests in a vacuum environment while upgrading the design of the bearings for improving their performance. These newly developed rotating mechanisms are employed in various solar missions such as the sounding rocket experiment CLASP and CLASP-2, and balloon-borne experiment SUNRISE-3., 形態: カラー図版あり, Physical characteristics: Original contains color illustrations

Published
2018

48. The solar photospheric convection in a tiny-scale derived by a new image restoration method for Hinode observation

Author

Sami, Solanki, Tino, Riethmueller, Oba, Takayoshi, Iida, Yusuke, and Shimizu, Toshifumi

Abstract

第17回宇宙科学シンポジウム (2017年1月5日-6日. 宇宙航空研究開発機構宇宙科学研究所(JAXA)(ISAS)相模原キャンパス), 相模原市, 神奈川県, 17th Space Science Symposium (January 5-6, 2017. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency(JAXA)(ISAS)Sagamihara Campus), Sagamihara, Kanagawa Japan, 資料番号: SA6000060164, レポート番号: P-122

Published
2017

49. Naを推進剤に用いた高性能パルスプラズマスラスタの開発研究

Author

Nonomura, Masaya, Yamada, Yoshinobu, Akimoto, Yuta, Taniguchi, Tsubasa, Ikeyama, Toru, Iida, Yusuke, and Fukuda, Takeshi

Abstract

平成28年度宇宙輸送シンポジウム（2017年1月19日-20日. 宇宙航空研究開発機構宇宙科学研究所（JAXA)(ISAS)）, 相模原市, 神奈川県, Space Transportation Symposium FY2016 (January 19-20, 2017. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA)(ISAS)), Sagamihara, Kanagawa Japan, 資料番号: SA6000086046, レポート番号: STEP-2016-008

Published
2017

Catalog

Books, media, physical & digital resources
See catalog results