研究者詳細 - 徳永　旭将

論文 - 徳永　旭将

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Global-Local Consistency for Cost-Effective Anomaly Localization with Point Annotations 査読有り国際誌

徳永旭将

2024 16th IIAI International Congress on Advanced Applied Informatics (IIAI-AAI) ( IEEE ) 2024年10月

担当区分：最終著者,　責任著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

Creating pixel-level ground-truth (GT) masks is quite costly for deep learning-based image segmentation. Specialists in areas such as anomaly detection and medical diagnostics face difficulties in producing many GT masks due to limited resources. To reduce this burden, we propose a cost-effective image segmentation framework with point annotations (CoSPA) that performs image segmentation with only point annotations. Point annotations refer to the partial and sparse labeled coordinates in an image. The key idea is to ensure consistency between the predictions for the same coordinates from the two different networks of CoSPA. This new consistency enables the CoSPA to improve segmentation performance and extend to semi-supervised learning. For the MVTec AD dataset, we verified the cost-effectiveness of CoSPA through an anomaly detection task. We demonstrated that the point annotating costs were reduced by 80% compared to creating GT masks. Subsequently, the CoSPA realized by 87% of the mean Intersection over Union (mIoU) achieved using the fully supervised method, DeepLabV3+. Moreover, the mIoU of CoSPA using only 30% of all point annotations defeated that of the unsupervised method, PaDiM. This study offers a new direction for economic anomaly localization.

CiNii Research

その他リンク： https://kyutech.repo.nii.ac.jp/records/2000992

Bidirectional 2D Reservoir Computing for Image Anomaly Detection without any Training 査読有り国際誌

Keiichi Nakanishi, Terumasa Tokunaga

Nonlinear Theory and Its Applications ( The Institute of Electronics, Information and Communication Engineers ) 15 ( 4 ) 838 - 850 2024年10月

Mechanism of sensory perception unveiled by simultaneous measurement of membrane voltage and intracellular calcium 査読有り国際誌

Terumasa Tokunaga, Noriko Sato, Mary Arai, Takumi Nakamura, Takeshi Ishihara

Communications Biology, ( Nature Portfolio (Springer Nature) ) 7 ( 1150 ) 2024年09月

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

Measuring neuronal activity is important for understanding neuronal function. Ca2+ imaging by genetically encoded calcium indicators (GECIs) is a powerful way to measure neuronal activity. Although it revealed important aspects of neuronal function, measuring the neuronal membrane voltage is important to understand neuronal function as it triggers neuronal activation. Recent progress of genetically encoded voltage indicators (GEVIs) enabled us fast and precise measurements of neuronal membrane voltage. To clarify the relation of the membrane voltage and intracellular Ca2+, we analyzed neuronal activities of olfactory neuron AWA in Caenorhabditis elegans by GCaMP6f (GECI) and paQuasAr3 (GEVI) responding to odorants. We found that the membrane voltage encodes the stimuli change by the timing and the duration by the weak semi-stable depolarization. However, the change of the intracellular Ca2+ encodes the strength of the stimuli. Furthermore, ODR-3, a G-protein alpha subunit, was shown to be important for stabilizing the membrane voltage. These results suggest that the combination of calcium and voltage imaging provides a deeper understanding of the information in neural circuits. (Figure presented.)

DOI： 10.1038/s42003-024-06778-2

Scopus

その他リンク： https://link.springer.com/article/10.1038/s42003-024-06778-2

Global-Local Consistency for Cost-Effective Anomaly Localization with Point Annotations 査読有り国際誌

Keiichi Nakanishi, Ryoya Katafuchi, Terumasa Tokunaga

The proceedings of 16th IIAI International Congress on Advanced Applied Informatics ( IEEE Computer Society ) 53 - 57 2024年07月

担当区分：最終著者,　責任著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

日本高松 2024年07月06日 - 2024年07月12日

DOI： 10.1109/IIAI-AAI63651.2024.00019

Kyutacar

Scopus

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85208092849&origin=inward

Layer-wise External Attention by well-localized attention map for efficient deep anomaly detection 招待有り査読有り国際誌

Keiichi Nakanishi, Ryo Shiroma, Tokihisa Hayakawa, Ryoya Katafuchi, Terumasa Tokunaga

SN Computer Science ( Springer Nature ) 592 ( 5 ) 2024年05月

担当区分：最終著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

The external attention mechanism offers a promising approach to enhance image anomaly detection (Hayakawa et al., in: IMPROVE, pp. 100-–110, 2023). Nevertheless, the effectiveness of this method is contingent upon the judicious selection of an intermediate layer with external attention. In this study, we performed a comprehensive series of experiments to clarify the mechanisms through which external attention improves detection performance. We assessed the performance of the LEA-Net (Hayakawa et al., in: IMPROVE, pp. 100–110, 2023), which implements layer-wise external attention, using MVTec AD and Plant Village datasets. The detection performances of the LEA-Net were compared with that of the baseline model under different anomaly maps generated by three unsupervised approaches. In addition, we investigated the relationship between the detection performance of LEA-Net and the selection of an attention point, which means an intermediate layer where external attention is applied. The findings reveal that the synergy between the dataset and the generated anomaly map influenced the effectiveness of the LEA-Net. For poorly localized anomaly maps, the selection of the attention point becomes a pivotal factor in determining detection efficiency. At shallow attention points, a well-localized attention map successfully notably improves the detection performance. For deeper attention points, the overall intensity of the attention map is essential; this intensity can be substantially amplified by layer-wise external attention, even for a low-intensity anomaly map. Overall, the results suggest that for layer-wise external attention, the positional attributes of anomalies hold greater significance than the overall intensity or visual appearance of the anomaly map.

DOI： 10.1007/s42979-024-02912-3

Kyutacar

その他リンク： https://www.scopus.com/record/display.uri?eid=2-s2.0-85194873765&origin=resultslist

Layer-Wise External Attention by Well-Localized Attention Map for Efficient Deep Anomaly Detection 招待有り査読有り国際誌

徳永旭将

SN Computer Science ( Springer ) 5 ( 5 ) 592 2024年05月

担当区分：最終著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

CiNii Research

その他リンク： https://kyutech.repo.nii.ac.jp/records/2000766

Bidirectional 2D reservoir computing for image anomaly detection without any training 査読有り国際誌

Nakanishi K., Tokunaga T.

Nonlinear Theory and its Applications, IEICE 15 ( 4 ) 838 - 850 2024年01月

担当区分：最終著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

Image anomaly detection is a crucial task in computer vision, where convolutional neural networks (CNN) often deliver exceptional performances. Hardware implementation of machine learning models is also important for achieving inference speed-up and power savings. However, the massive number of CNN parameters poses challenges for hardware implementation. This study introduces reservoir computing (RC) to create a compact image processor without training, thereby enabling scalable deployment. Our proposed bidirectional 2-dimensional reservoir computing (BiRC2D) is a feature extractor based on RC. Experiments conducted on the MVTec AD dataset, a benchmark dataset for real-world anomaly detection task, validated the efficacy of BiRC2D when integrated into the patch distribution modeling (PaDiM) framework. The mean intersection over union (mIoU) score from PaDiM with BiRC2D outperformed or was comparable to the mIoU score from PaDiM with ResNet-50 in several categories while reducing the parameter count by up to 98%.

DOI： 10.1587/nolta.15.838

Scopus

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=105002778025&origin=inward

Layer-wise External Attention for Efficient Deep Anomaly Detection 査読有り

Tokihisa Hayakawa, Keiichi Nakanishi, Ryoya Katafuchi, Terumasa Tokunaga

Proceedings of the 3rd International Conference on Image Processing and Vision Engineering ( SCITEPRESS - Science and Technology Publications ) 100 - 110 2023年01月

担当区分：最終著者,　責任著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

チェコプラハ

DOI： 10.5220/0011856800003497

CiNii Research

その他リンク： https://www.scitepress.org/Link.aspx?doi=10.5220/0011856800003497

Behavioral forgetting of olfactory learning is mediated by interneuron-regulated network plasticity in Caenorhabditis elegans 査読有り国際誌

Jamine Teo, Itsuki Kurokawa, Yuuki Onishi, Noriko Sato, Tomohiro Kitazono, Terumasa Tokunaga, Manabi Fujiwara, Takeshi Ishihara

eNeuro ( the Society for Neuroscience ) 9 ( 4 ) 2022年08月

記述言語：英語掲載種別：研究論文（学術雑誌）

Forgetting is important for animals to manage acquired memories to enable adaptation to changing environments; however, the neural network in mechanisms of forgetting is not fully understood. To understand the mechanisms underlying forgetting, we examined olfactory adaptation, a form of associative learning, in Caenorhabditis elegans (C. elegans). The forgetting of diacetyl olfactory adaptation in C. elegans is regulated by secreted signals from AWC sensory neurons via the TIR-1/JNK-1 pathway. These signals cause a decline of the sensory memory trace in AWA neurons where diacetyl is mainly sensed. To further understand the neural network that regulates this forgetting, we investigated the function of interneurons downstream of AWA and AWC neurons. We found that a pair of interneurons, AIA, is indispensable for the proper regulation of behavioral forgetting of diacetyl olfactory adaptation. Loss of or inactivation of AIA caused the impairment of the chemotaxis recovery after adaptation without causing severe chemotaxis defects in naïve animal. AWA Ca2+ imaging analyses suggested that loss or inactivation of AIA interneurons did not affect the decline of the sensory memory trace after the recovery. Furthermore, AIA responses to diacetyl were observed in naïve and after the recovery, but not just after the conditioning, suggesting that AIA responses after the recovery are required for the chemotaxis to diacetyl. We propose that the functional neuronal circuit for attractive chemotaxis to diacetyl is changed temporally at the recovery phase so that AIA interneurons are required for chemotaxis, although AIAs are dispensable for attractive chemotaxis to diacetyl in naïve animals.

DOI： https://doi.org/10.1523/ENEURO.0084-22.2022

その他リンク： https://www.eneuro.org/content/early/2022/08/17/ENEURO.0084-22.2022

半教師あり二値分類のためのクラス事前確率を用いたコスト関数の提案査読有り

中西慶一, 徳永旭将

第25回画像の認識・理解シンポジウム ( 情報処理学会コンピュータビジョンとイメージメディア(CVIM)研究会 ) 2022年07月

担当区分：最終著者,　責任著者記述言語：日本語掲載種別：研究論文（研究会，シンポジウム資料等）

日本姫路 2022年07月25日 - 2022年07月28日

本稿は半教師あり二値分類のための新しいコスト関数を提案する. 提案するコスト関数は, Focal Loss を半教師あり分類のために拡張した損失関数とクラス事前確率罰則項から構成される. クラス事前確率罰則項を導入することで, ラベルなしデータにおける正例の割合がわかる場合, その事前情報を直接的に推論に活用することが可能である. 提案するコスト関数の有用性を評価するため, CIFAR-10 を用いた画像二値分類試験を行った. その結果, 少量のラベルありデータセットや不均衡なデータセットにおいて, 提案するコスト関数は既存のコスト関数と比べて優れた性能を示すことを確認した.

その他リンク： https://sites.google.com/view/miru2022/program#h.44rbhnwbmvlj

Behavioral Forgetting of Olfactory Learning Is Mediated by Interneuron-Regulated Network Plasticity in Caenorhabditis elegans 査読有り

Teo J.H.M., Kurokawa I., Onishi Y., Sato N., Kitazono T., Tokunaga T., Fujiwara M., Ishihara T.

eNeuro 9 ( 4 ) 2022年07月

記述言語：英語掲載種別：研究論文（学術雑誌）

Forgetting is important for animals to manage acquired memories to enable adaptation to changing environments; however, the neural network in mechanisms of forgetting is not fully understood. To understand the mechanisms underlying forgetting, we examined olfactory adaptation, a form of associative learning, in Caenorhabditis elegans. The forgetting of diacetyl olfactory adaptation in C. elegans is regulated by secreted signals from AWC sensory neurons via the TIR-1/JNK-1 pathway. These signals cause a decline of the sensory memory trace in AWA neurons, where diacetyl is mainly sensed. To further understand the neural network that regulates this forgetting, we investigated the function of interneurons downstream of AWA and AWC neurons. We found that a pair of interneurons, AIA, is indis-pensable for the proper regulation of behavioral forgetting of diacetyl olfactory adaptation. Loss or inactivation of AIA caused the impairment of the chemotaxis recovery after adaptation without causing severe chemotaxis defects in the naive animal. AWA Ca2+ imaging analyses suggested that loss or inactivation of AIA interneurons did not affect the decline of the sensory memory trace after the recovery. Furthermore, AIA responses to diacetyl were observed in naive animals and after the recovery, but not just after the conditioning, suggesting that AIA responses after the recovery are required for the chemotaxis to diacetyl. We propose that the functional neuronal circuit for attractive chemo-taxis to diacetyl is changed temporally at the recovery phase so that AIA interneurons are required for chemotaxis, although AIAs are dispensable for attractive chemotaxis to diacetyl in naive animals.

DOI： 10.1523/ENEURO.0084-22.2022

Kyutacar

Scopus

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85137058885&origin=inward

Signal and Noise Separation from Satellite Magnetic Field Data through Independent Component Analysis: Prospect of Magnetic Measurements without Boom and Noise Source Information 査読有り国際誌

Shun Imajo, Masahito Nosé, Mari Aida, Haruhisa Matsumoto, Nana Higashio, Terumasa Tokunaga , Ayako Matsuoka

Journal of Geophysical Research: Space Physics ( American Geophysical Union ) 126 ( 5 ) 2021年04月

Image-based Plant Disease Diagnosis with Unsupervised Anomaly Detection based on Reconstructability of Colors 査読有り国際誌

Katafuchi, R. and Tokunaga, T.

In Proceedings of the International Conference on Image Processing and Vision Engineering - IMPROVE ( SciTePress ) 112 - 120 2021年04月

担当区分：最終著者,　責任著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

Virtual Virtual 2021年04月28日 - 2021年04月30日

This paper proposes an unsupervised anomaly detection technique for image-based plant disease diagnosis. The construction of large and publicly available datasets containing labeled images of healthy and diseased crop plants led to growing interest in computer vision techniques for automatic plant disease diagnosis. Although supervised image classifiers based on deep learning can be a powerful tool for plant disease diagnosis, they require a huge amount of labeled data. The data mining technique of anomaly detection includes unsupervised approaches that do not require rare samples for training classifiers. We propose an unsupervised anomaly detection technique for image-based plant disease diagnosis that is based on the reconstructability of colors; a deep encoder-decoder network trained to reconstruct the colors of healthy plant images should fail to reconstruct colors of symptomatic regions. Our proposed method includes a new image-based framework for plant disease detection that u tilizes a conditional adversarial network called pix2pix and a new anomaly score based on CIEDE2000 color difference. Experiments with PlantVillage dataset demonstrated the superiority of our proposed method compared to an existing anomaly detector at identifying diseased crop images in terms of accuracy, interpretability and computational efficiency.

DOI： 10.5220/0010463201120120

Scopus

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85115692116&origin=inward

Cohesive and anisotropic vascular endothelial cell motility driving angiogenic morphogenesis 査読有り国際誌

Takubo N., Yura F., Naemura K., Yoshida R., Tokunaga T., Tokihiro T., Kurihara H.

Scientific Reports ( Nature Publishing Group ) 9 ( 1 ) 9304-1 - 9304-9 2019年12月

記述言語：英語掲載種別：研究論文（学術雑誌）

Vascular endothelial cells (ECs) in angiogenesis exhibit inhomogeneous collective migration called “cell mixing”, in which cells change their relative positions by overtaking each other. However, how such complex EC dynamics lead to the formation of highly ordered branching structures remains largely unknown. To uncover hidden laws of integration driving angiogenic morphogenesis, we analyzed EC behaviors in an in vitro angiogenic sprouting assay using mouse aortic explants in combination with mathematical modeling. Time-lapse imaging of sprouts extended from EC sheets around tissue explants showed directional cohesive EC movements with frequent U-turns, which often coupled with tip cell overtaking. Imaging of isolated branches deprived of basal cell sheets revealed a requirement of a constant supply of immigrating cells for ECs to branch forward. Anisotropic attractive forces between neighboring cells passing each other were likely to underlie these EC motility patterns, as evidenced by an experimentally validated mathematical model. These results suggest that cohesive movements with anisotropic cell-to-cell interactions characterize the EC motility, which may drive branch elongation depending on a constant cell supply. The present findings provide novel insights into a cell motility-based understanding of angiogenic morphogenesis.

DOI： 10.1038/s41598-019-45666-2

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85068037379&origin=inward

SPF-CellTracker: Tracking Multiple Cells with Strongly-Correlated Moves Using a Spatial Particle Filter 査読有り国際誌

Hirose O., Kawaguchi S., Tokunaga T., Toyoshima Y., Teramoto T., Kuge S., Ishihara T., Iino Y., Yoshida R.

IEEE/ACM Transactions on Computational Biology and Bioinformatics ( Institute of Electrical and Electronics Engineers Inc. ) 15 ( 6 ) 1822 - 1831 2018年11月

記述言語：英語掲載種別：研究論文（学術雑誌）

© 2004-2012 IEEE. Tracking many cells in time-lapse 3D image sequences is an important challenging task of bioimage informatics. Motivated by a study of brain-wide 4D imaging of neural activity in C. elegans, we present a new method of multi-cell tracking. Data types to which the method is applicable are characterized as follows: (i) cells are imaged as globular-like objects, (ii) it is difficult to distinguish cells on the basis of shape and size only, (iii) the number of imaged cells in the several-hundred range, (iv) movements of nearly-located cells are strongly correlated, and (v) cells do not divide. We developed a tracking software suite that we call SPF-CellTracker. Incorporating dependency on the cells' movements into the prediction model is the key for reducing the tracking errors: the cell switching and the coalescence of the tracked positions. We model the target cells' correlated movements as a Markov random field and we also derive a fast computation algorithm, which we call spatial particle filter. With the live-imaging data of the nuclei of C. elegans neurons in which approximately 120 nuclei of neurons were imaged, the proposed method demonstrated improved accuracy compared to the standard particle filter and the method developed by Tokunaga et al. (2014).

DOI： 10.1109/TCBB.2017.2782255

Scopus

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85038382107&origin=inward

線虫の全脳活動データに対する位相解析

岩崎唯史, 寺本孝行, 大江紗, 徳永旭将, 広瀬修, 豊島有, ジャンムンソン, 吉田亮, 飯野雄一, 石原健

日本物理学会講演概要集 ( 一般社団法人日本物理学会 ) 72.1 ( 0 ) 2817 - 2817 2017年01月

記述言語：日本語掲載種別：研究論文（大学，研究機関等紀要）

線虫C. elegansの神経系は302個の神経細胞から構成され，そのうち約170個が頭部に集中している．頭部に存在するこれら神経細胞の同時イメージングデータに対して，同期/非同期オーダーパラメータを用いた位相解析，および類似度行列に基づいたクラスタ解析を行った．本発表ではこれらの結果について報告する．また，シナプス結合に異常がある変異体での結果と野生型での結果の違いについても言及する．

DOI： 10.11316/jpsgaiyo.72.1.0_2817

CiNii Article

CiNii Research

Accurate Automatic Detection of Densely Distributed Cell Nuclei in 3D Space 査読有り国際誌

Toyoshima Y., Tokunaga T., Hirose O., Kanamori M., Teramoto T., Jang M.S., Kuge S., Ishihara T., Yoshida R., Iino Y.

PLoS Computational Biology ( Public Library of Science ) 12 ( 6 ) 2016年06月

記述言語：英語掲載種別：研究論文（学術雑誌）

To measure the activity of neurons using whole-brain activity imaging, precise detection of each neuron or its nucleus is required. In the head region of the nematode C. elegans, the neuronal cell bodies are distributed densely in three-dimensional (3D) space. However, no existing computational methods of image analysis can separate them with sufficient accuracy. Here we propose a highly accurate segmentation method based on the curvatures of the iso-intensity surfaces. To obtain accurate positions of nuclei, we also developed a new procedure for least squares fitting with a Gaussian mixture model. Combining these methods enables accurate detection of densely distributed cell nuclei in a 3D space. The proposed method was implemented as a graphical user interface program that allows visualization and correction of the results of automatic detection. Additionally, the proposed method was applied to time-lapse 3D calcium imaging data, and most of the nuclei in the images were successfully tracked and measured.

DOI： 10.1371/journal.pcbi.1004970

Scopus

PubMed

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84978903985&origin=inward

Automated detection and tracking of many cells by using 4D live-cell imaging data 査読有り

Tokunaga T., Hirose O., Kawaguchi S., Toyoshima Y., Teramoto T., Ikebata H., Kuge S., Ishihara T., Iino Y., Yoshida R.

Bioinformatics ( Oxford University Press ) 30 ( 12 ) 2014年06月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

Motivation: Automated fluorescence microscopes produce massive amounts of images observing cells, often in four dimensions of space and time. This study addresses two tasks of time-lapse imaging analyses; detection and tracking of the many imaged cells, and it is especially intended for 4D live-cell imaging of neuronal nuclei of Caenorhabditis elegans. The cells of interest appear as slightly deformed ellipsoidal forms. They are densely distributed, and move rapidly in a series of 3D images. Thus, existing tracking methods often fail because more than one tracker will follow the same target or a tracker transits from one to other of different targets during rapid moves. Results: The present method begins by performing the kernel density estimation in order to convert each 3D image into a smooth, continuous function. The cell bodies in the image are assumed to lie in the regions near the multiple local maxima of the density function. The tasks of detecting and tracking the cells are then addressed with two hill-climbing algorithms. The positions of the trackers are initialized by applying the cell-detection method to an image in the first frame. The tracking method keeps attacking them to near the local maxima in each subsequent image. To prevent the tracker from following multiple cells, we use a Markov random field (MRF) to model the spatial and temporal covariation of the cells and to maximize the image forces and the MRF-induced constraint on the trackers. The tracking procedure is demonstrated with dynamic 3D images that each contain >100 neurons of C.elegans. © 2014 The Author. Published by Oxford University Press. All rights reserved.

DOI： 10.1093/bioinformatics/btu271

Scopus

PubMed

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84902509846&origin=inward

3次元動画像内の非常に多数の細胞領域を自動追跡するための粒子フィルタ手法の開発

広瀬修, 川口翔太郎, 徳永旭将, 豊島有, 寺本孝行, 佐藤賢二, 池端久貴, 佐藤博文, 久下小百合, 石原健, 飯野雄一, 吉田亮

人工知能学会全国大会論文集 ( 一般社団法人人工知能学会 ) JSAI2014 ( 0 ) 2C32in - 2C32in 2014年01月

記述言語：日本語掲載種別：研究論文（研究会，シンポジウム資料等）

細胞動画像の典型的な特徴として多数の追跡対象物が密に存在し視覚的に類似していることが挙げられる．このような動画像に対し標準的な粒子フィルタを利用した場合，本来の追跡対象を別の対象物と誤認し追跡に容易に失敗する．この問題に対し多数の細胞の共変動性に着目し追跡のための補助情報としてこれを利用することで追跡精度の向上を目指す．

DOI： 10.11517/pjsai.jsai2014.0_2c32in

CiNii Article

CiNii Research

データ同化によって線虫の神経回路をまるごと読み解く : 現状と課題招待有り査読有り

徳永旭将, 吉田亮, 岩崎唯史

シミュレーション = Journal of the Japan Society for Simulation Technology / 日本シミュレーション学会編 ( 東京 : 小宮山印刷工業 ) 32 ( 4 ) 287 - 294 2013年12月

Extraction of groove feelings from drum data using non-negative matrix factorization 査読有り

Ohya Y., Nakamura K., Tokunaga T.

6th International Conference on Soft Computing and Intelligent Systems, and 13th International Symposium on Advanced Intelligence Systems, SCIS/ISIS 2012 125 - 130 2012年12月

担当区分：最終著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

In this paper, we propose the algorithm to extract the groove feeling from drum data. In the previous researches, extraction of the groove feeling requires pre-separated acoustic sources. We employed non-negative matrix factorization (NMF) to make separated information on hitting time from monaural wave data in which multiple acoustic sources are mixed. We applied our algorithm to a drum data and obtained a difference of time fluctuations among instruments, which relates to groove feeling and impression. The result implies that the proposed algorithm can extract some sensitive differences of nuance of drumming. © 2012 IEEE.

DOI： 10.1109/SCIS-ISIS.2012.6505312

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84877794120&origin=inward

Separation of stationary and non-stationary sources with a generalized eigenvalue problem 査読有り

Hara S., Kawahara Y., Washio T., von Bünau P., Tokunaga T., Yumoto K.

Neural Networks 33 7 - 20 2012年09月

記述言語：英語掲載種別：研究論文（学術雑誌）

Non-stationary effects are ubiquitous in real world data. In many settings, the observed signals are a mixture of underlying station ary and non-stationary sources that cannot be measured directly. For example, in EEG analysis, electrodes on the scalp record the activity from several sources located inside the brain, which one could only measure invasively. Discerning stationary and non-stationary contributions is an important step towards uncovering the mechanisms of the data generating system. To that end, in Stationary Subspace Analysis (SSA), the observed signal is modeled as a linear superposition of stationary and non-stationary sources, where the aim is to separate the two groups in the mixture. In this paper, we propose the first SSA algorithm that has a closed form solution. The novel method, Analytic SSA (ASSA), is more than 100 times faster than the state-of-the-art, numerically stable, and guaranteed to be optimal when the covariance between stationary and non-stationary sources is time-constant. In numerical simulations on wide range of settings, we show that our method yields superior results, even for signals with time-varying group-wise covariance. In an application to geophysical data analysis, ASSA extracts meaningful components that shed new light on the Pi 2 pulsations of the geomagnetic field. © 2012 Elsevier Ltd.

DOI： 10.1016/j.neunet.2012.04.001

Scopus

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Onset time determination of precursory events in time series data by an extension of Singular Spectrum Transformation 招待有り査読有り国際誌

Tokunaga T., Ikeda D., Nakamura K., Higuchi T., Yoshikawa A., Uozumi T., Fujimoto A., Morioka A., Yumoto K.

International Journal of Circuits, Systems and Signal Processing 5 ( 1 ) 46 - 60 2011年10月

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

To predict an occurrence of extraordinary phenomena, such as earthquakes, failures of engineering systems and financial market crushes, it is important to identify precursory events in time series. However, existing methods are limited in their applicability for real world precursor detections. Recently, Ide and Inoue [1] have developed an SSA-based change-point detection method, called singular spectrum transformation (SST). SST is suitable for detecting various types of change-points, but real world precursor detections can be far more difficult than expected. In general, precursory events are observed as minute and less-visible fluctuations preceding an onset of massive fluctuations of extraordinary phenomena and therefore they are easily over-looked. To overcome this point, we extend the conventional SST to the multivariable SST. The originality of our strategy is in focusing on synchronism detections of precursory events in multiple sequences of univariate time series. We performed some experiments by using artificial data and showed the superiority of multivariable SST in detecting onset of precursory events. Furthermore, the superiority is also shown statistically in determining the onset of precursory events by using real world time series.

Scopus

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Identification of full-substorm onset from ground-magnetometer data by singular value transformation 査読有り

徳永旭将, 湯元清文, 魚住禎司, CPMNグループ

Memoirs of the Faculty of Science, Kyushu University. Series D, Earth and planetary sciences ( 九州大学大学院理学研究院 ) 32 ( 3 ) 63 - 73 2011年03月

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（大学，研究機関等紀要）

Pi 2 magnetic pulsations observed on the ground are a good indicator of the auroral breakup. However, they have not only corresponding full-substorm onsets but also most pseudobreakups. Another well-known substorm related phenomenon observed on the ground is positive bays. In order to identify full-substorm onsets from ground-magnetometer data, we developed a new algorithm based on "Singular Spectrum Analysis(SSA)". The algorithm enables us to screen Pi 2 pulsations accompanied by the magnetic positive bay. We applied proposed algorithm to ground-magnetometer data and compared to the obtained results with Polar/UVI data. As a result, we succeeded in identifying 62% of the full-substorm onsets from ground-magnetometer data obtained in the nighttime sector between 21 and 03LT.

DOI： 10.5109/19197

CiNii Article

CiNii Research

変化点検出を応用した時系列データからの突発現象の前兆検出アルゴリズム査読有り国際誌

徳永旭将, 池田大輔, 中村和幸

情報処理学会研究報告 ( 東京 : 情報処理学会 ) 2010年度 ( 5 ) 1 - 6 2011年02月

AKR modulation and global Pi2 oscillation 査読有り国際誌

Uozumi T., Yumoto K., Tokunaga T., Solovyev S., Shevtsov B., Marshall R., Liou K., Ohtani S., Abe S., Ikeda A., Kitamura K., Yoshikawa A., Kawano H., Itonaga M.

Journal of Geophysical Research: Space Physics 116 ( 6 ) 2011年01月

記述言語：英語掲載種別：研究論文（学術雑誌）

In this report we present a temporal relationship between ground Pi2 and auroral kilometric radiation (AKR). We analyzed six isolated substorm events, which were observed by the MAGDAS/CPMN ground magnetometer network and the plasma wave instrument onboard the Polar satellite. We found that the time derivative of the height-integrated AKR power and the ground Pi2 D component had the same periodicity and that the two were synchronized with each other. When the D component fluctuated with the same (opposite) polarity as the magnetic bay variation, the AKR power tended to increase (decrease) during the corresponding interval. An isolated substorm event (AE ∼ 40 nT), which occurred around 10:19 UT on 24 January1997, was selected for a detailed study. The behavior of the Pi2 event can be interpreted by the substorm current wedge (SCW) and Pi2 propagation models. It is confirmed that the midlatitude and high-latitude D component oscillations can be treated as a proxy of the SCW oscillations, whereas the H component oscillations exhibited some phase shifts by the propagation delay of the Pi2 waves. That is, the temporal relation between the time derivative of the AKR power and the ground Pi2 suggests that the height-integrated AKR power was modulated coherently with the SCW oscillations. Copyright 2011 by the American Geophysical Union.

DOI： 10.1029/2010JA016042

Scopus

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Identification of full-substorm onset from ground-magnetometer data by singular value transformation 査読有り

徳永旭将

Memoirs of the Faculty of Sciences, Kyushu University, Series D, Earth and Planetary Sciences 32 63 - 73 2011年01月

変化点検出を応用した時系列データからの突発現象の前兆検出アルゴリズム査読有り

徳永旭将, 池田大輔, 中村和幸, 樋口知之, 吉川顕正, 魚住禎司, 藤本晶子, 森岡昭, 湯元清文, CpmnGroup

研究報告バイオ情報学（BIO） 2010 ( 14 ) 1 - 6 2010年12月

担当区分：筆頭著者,　責任著者記述言語：日本語掲載種別：研究論文（国際会議プロシーディングス）

一般に，前兆現象は突発現象にそのものに比べて非常に目立ちにくく，その開始時刻は曖昧である．従来よく用いられてきた変化点検出法を適用した場合，このような微小で緩慢な変化は見逃されやすい．Tokunaga et al.1) では，Ide and Inoue2) の提案した特異スペクトル分析を応用した変化点検出法 (SST) を，多次元データを用いたアルゴリズム (MSST) へと拡張することで，鋭敏に前兆現象の開始時刻を推定出来ることを示した．MSST は，緩慢な変化も検出できる鋭敏な手法であるが，実データへの適用では誤検出が問題になる．本稿では，突発現象の大まかな開始時刻を予め検出し，さらに検出された時刻の前後で前兆現象の開始時刻と終了時刻を個別に探索することで，誤検出を劇的に減少させることができることを示す．

CiNii Article

CiNii Research

Detecting precursory events in time series data by an extension of singular spectrum transformation 査読有り国際誌

Tokunaga T., Ikeda D., Nakamura K., Higuchi T., Yoshikawa A., Uozumi T., Fujimoto A., Morioka A., Yumoto K.

International Conference on Applied Computer Science - Proceedings 366 - 374 2010年12月

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

To predict an occurrence of extraordinary phenomena, such as earthquakes, failures of engineering system and financial market crushes, it is important to identify precursory events in time series. However, existing methods are limited in their applicability for real world precursor detections. Recently, Ide and Inoue [1] have developed an SSA-based change-point detection method, called singular spectrum transformation (SST). In this paper, we extend the SST so that it is applicable for real world precursor detections, focusing on the wide applicability of the conventional SST. Although the SST is suitable for detecting various types of change-points, detecting precursors can be far more difficult than expected because, in general, real world time series contains measurement noise and non-stationary trends. Furthermore, precursory events are usually observed as minute and less-visible fluctuations preceding an onset of massive fluctuations of extraordinary phenomena and therefore they are easily over-looked. To overcome this, we extend the conventional SST to the multivariable SST, focusing on the synchronism detection of precursory events in multiple sequences of univariate time series. First, we would like to define the problem setting of real world precursory detections and consider its difficulties. Second, the multivariable SST is introduced. Third, we apply SST to geomagnetic time series data and show the multivariable SST is more suitable than the conventional SST for real world precursor detections. Finally, we show further experimental results using artificial data to evaluate the reliability of SST-based precursor detections.

Scopus

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Detecting Precursory Events in Time Series Data by an Extension of Singular Spectrum Transformation 査読有り国際誌

徳永旭将

Proceedings of the 10th WSEAS International Conference on Applied Computer Science 366 - 374 2010年01月

Onset Time Determination of Precursory Events of Singular Spectrum Transformation 招待有り査読有り国際誌

徳永旭将

International Journal of Circuits, Systems and Signal processing 5 46 - 60 2010年01月

Propagation characteristics of Pi 2 pulsations observed at high- And low-latitude MAGDAS/CPMN stations: A statistical study 査読有り

Uozumi T., Abe S., Kitamura K., Tokunaga T., Yoshikawa A., Kawano H., Marshall R., Morris R.J., Shevtsov B.M., Solovyev S.I., McNamara D.J., Liou K., Ohtani S., Itonaga M., Yumoto K.

Journal of Geophysical Research: Space Physics 114 ( 11 ) 2009年11月

記述言語：英語掲載種別：研究論文（学術雑誌）

The objective of this study is to understand better the propagation of Pi 2 waves in the nighttime region. We examined Pi 2 oscillations that showed high correlation between high- and low-latitude Magnetic Data Acquisition System/Circum Pan-Pacific Magnetometer Network stations (correlation coefficient: |γ| ≥ 0.75). For each horizontal component (H and D) we examined the magnetic local time (MLT) dependence of the delay time of high-latitude Pi 2 oscillations that corresponds to the highest correlation with the low-latitude Pi 2 oscillation. We found the delay time of the high-latitude H showed remarkable MLT dependence, especially in the premidnight sector: we found that in the premidnight sector the high-latitude H oscillation tends to delay from the low-latitude oscillation (<100 s). On the other hand, the delay time of the high-latitude D oscillation was not significant (∼±10 s) in the entire nighttime sector. We propose a Pi 2 propagation model to explain the observed delay time of high-correlation highlatitude H. The model quantitatively explains the trend of the event distribution. We also examined the spatial distribution of high-correlation Pi 2 events relative to the center of auroral breakups. It was found that the high-correlation Pi 2 events tend to occur away from the center of auroral breakups by more than 1.5 MLT. The present result suggests that the high-correlation H component Pi 2 oscillations at high latitude are a manifestation of forced Alfvén waves excited by fast magnetosonic waves. Copyright 2009 by the American Geophysical Union.

DOI： 10.1029/2009JA014163

Scopus

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A new index to monitor temporal and long-term variations of the equatorial electrojet by MAGDAS/CPMN real-time data: EE-index 査読有り

Uozumi T., Yumoto K., Kitamura K., Abe S., Kakinami Y., Shinohara M., Yoshikawa A., Kawano H., Ueno T., Tokunaga T., McNamara D., Ishituka J.K., Dutra S.L.G., Damtie B., Doumbia V., Obrou O., Rabiu A.B., Adimula I.A., Othman M., Fairos M., Otadoy R.E.S.

Earth, Planets and Space 60 ( 7 ) 785 - 790 2008年01月

記述言語：英語掲載種別：研究論文（学術雑誌）

A new index, EE-index (EDst, EU, and EL), is proposed to monitor temporal and long-term variations of the equatorial electrojet by using the MAGDAS/CPMN real-time data. The mean value of the H component magnetic variations observed at the nightside (LT = 18-06) MAGDAS/CPMN stations along the magnetic equatorial region is found to show variations similar to those of Dst; we defined this quantity as EDst. The EDst can be used as a proxy of Dst for the real-time and long-term geospace monitoring. By subtracting EDst from the H component data of each equatorial station, ir is possible to extract the Equatorial Electrojet and Counter Electrojetcomponents, which are defined as EU and EL, respectively. Copyright © The Society of Geomagnetism and Earth, Planetary and Space Sciences (SGEPSS).

DOI： 10.1186/BF03352828

Scopus

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Global features of Pi 2 pulsations obtained by independent component analysis 査読有り国際誌

Tokunaga T., Kohta H., Yoshikawa A., Uozumi T., Yumoto K.

Geophysical Research Letters ( American Geophysical Union ) 34 ( 14 ) 2007年07月

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

Ground Pi 2 pulsations are mixtures of several components reflecting (1) propagations of fast and shear Alfvén wave, (2) resonances of plasmaspheric/magnetospheric cavity and magnetic field lines, and (3) tansformations to ionospheric current systems. However, it has been unclear how they coupled with each other and how their signals are distributed at different latitudes. The present work is intended to pilot the future possibilities whether we can identify the global system of Pi 2 pulsations by Independent Component Analysis (ICA). We have successfully decomposed an isolated Pi 2 event on a quiet day observed at the CPMN stations into two components. One was the global oscillation that occurs from nightside high to equatorial latitudes with the common waveform and has an amplitude maximum at nightside high latitude. Another component was localized at nightside high latitudes. Its amplitudes were quite weak at low latitudes, but were enhanced near dayside dip equator. Copyright 2007 by the American Geophysical Union.

DOI： 10.1029/2007GL030174

Scopus

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High-top clouds play an efficient part in moisture transport to the Antarctic

Kazue Suzuki, Terumasa Tokunaga, Takashi Yamanouchi, Hideaki Motoyama

ESS Open Archive ( Wiley and Authorea ) 2022年08月

Identifying Snowfall Clouds at Syowa Station, Antarctica via a Convolutional Neural Network 査読有り国際誌

Kazue Suzuki, Masaki Shimomura, Kazuyuki Nakamura, Naohiko Hirasawa, Hironori Yabuki, Takashi Yamanouchi, Terumasa Tokunaga

Advances in Artificial Intelligence - Selected Papers from the Annual Conference of Japanese Society of Artificial Intelligence (JSAI 2020) ( Springer International Publishing ) 1357 ( 1 ) 78 - 83 2021年07月

CNNを用いた南極・昭和基地に降雪をもたらす雲識別

鈴木香寿恵, 下村真生, 中村和幸, 平沢尚彦, 矢吹裕伯, 山内恭, 徳永旭将

人工知能学会全国大会論文集 ( 一般社団法人人工知能学会 ) 2020 ( 0 ) 3F1ES205 - 3F1ES205 2020年01月

担当区分：最終著者記述言語：英語掲載種別：研究論文（学術雑誌）

近年の温暖化環境における南極氷床の涵養量の変動のふるまいは、地球全体の水収支に大きな影響を及ぼすことから関心が高まっているが，その厳しい環境や降雪量の観測自体が難しいという現状である。限定された観測データを組み合わせ降雪量推定モデルの開発を行ってきた。今回は南極・昭和基地において観測された降雪時の雲画像に対して、CNNを適用し，二値および三値の自動識別を試みた。「Atmospheric River」と呼ばれる高高度の連なる雲が降雪に寄与しているとし，その雲構造をもつ降雪時の画像を正例，その雲構造がない，もしくは画像視野が十分でない場合準正例とした。ネットワーク構造としてはVGG16にInception構造を加え，全結合層をGlobal Average Poolingに置き換えてパラメタ数を削減した。学習に対し正例138, 準正例477, 負例511のサンプルを用いた。二値問題には正例と準正例を正例として扱った。識別精度は，二値(三値)分類は71.00%(65.37%)であった。 Grad-CAMによる可視化結果は三値分類時に雲構造を捉えられている様子を示していた。

DOI： 10.11517/pjsai.JSAI2020.0_3F1ES205

CiNii Article

CiNii Research

その他リンク： https://ci.nii.ac.jp/naid/130007857079

計測，モデル，データ科学はどのように協調できるか？招待有り査読有り

徳永旭将

計測と制御 ( 公益社団法人計測自動制御学会 ) 58 ( 3 ) 166 - 170 2019年03月

ディープラーニングによる南極昭和基地周辺における降雪をもたらす雲の検出

鈴木香寿恵, 徳永旭将, 福地岬稀, 平沢尚彦, 山内恭

雪氷研究大会講演要旨集 ( 公益社団法人日本雪氷学会／日本雪工学会 ) 2019 ( 0 ) 119 2019年01月

線虫の全中枢神経細胞活動データに対する因果性解析II

岩崎唯史, 佐藤博文, 大江紗, 久下小百合, 寺本孝行, 徳永旭将, 広瀬修, 豊島有, ジャンムンソン, 吉田亮, 飯野雄一, 石原健

日本物理学会講演概要集 ( 一般社団法人日本物理学会 ) 73.2 ( 0 ) 2315 - 2315 2018年01月

線虫の全中枢神経細胞活動データに対する因果性解析

岩崎唯史, 佐藤博文, 大江紗, 寺本孝行, 徳永旭将, 広瀬修, 豊島有, ジャンムンソン, 吉田亮, 飯野雄一, 石原健

日本物理学会講演概要集 ( 一般社団法人日本物理学会 ) 73.1 ( 0 ) 2853 - 2853 2018年01月

線虫の全脳活動データに対する位相解析

岩崎唯史, 寺本孝行, 大江紗, 徳永旭将, 広瀬修, S. Wu, 豊島有, ジャンムンソン, 吉田亮, 飯野雄一, 石原健

2017年度日本物理学会第72回年次大会講演集 ( 一般社団法人日本物理学会 ) 2017年03月

空間粒子フィルタによる多数の細胞の同時追跡

広瀬修, 川口翔太朗, 徳永旭将

電子情報通信学会技術研究報告 = IEICE technical report : 信学技報 ( 東京 : 電子情報通信学会 ) 115 ( 112 ) 137 - 141 2015年06月

データ同化によって線虫の神経回路をまるごと読み解く : 現状と課題招待有り査読有り

徳永旭将, 吉田亮, 岩崎唯史

Journal of The Japan Society for Simulation Technology ( 日本シミュレーション学会 ) 32 ( 4 ) 287 - 294 2013年12月

Annual and semi-annual Sq variations at 96° MM MAGDAS I and II stations in Africa 査読有り国際誌

El Hawary R., Yumoto K., Yamazaki Y., Mahrous A., Ghamry E., Meloni A., Badi K., Kianji G., Uiso C., Mwiinga N., Joao L., Affluo T., Sutcliffe P., Mengistu G., Baki P., Abe S., Ikeda A., Fujimoto A., Tokunaga T.

Earth, Planets and Space 64 ( 6 ) 425 - 432 2012年01月

記述言語：英語掲載種別：研究論文（学術雑誌）

The quiet daily variations of the geomagnetic field (S q ) have been studied by using the geomagnetic data of the 10 International Quietest Days. Geomagnetic data from MAGDAS I and II stations - ten stations were selected around the 96° magnetic meridian (MM) - over Africa have been analyzed from September 2008 to August 2009. The analysis of this unique data set clarifies the characteristics of the S q variations over the African sector for the first time by observational geomagnetic data. In this paper, we found that S q (H) and S q (D) show a predominantly annual variation. The most interesting result, and a new finding in the African sector, is the appearance of two vortices in the day lit southern hemisphere during spring. Further data analysis also revealed many other interesting characteristics for the S q over the African sector. Copyright © The Society of Geomagnetism and Earth, Planetary and Space Sciences (SGEPSS).

DOI： 10.5047/eps.2011.10.013

Scopus

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Pi 2 waves simultaneously observed by Cluster and CPMN ground-based magnetometers near the plasmapause 査読有り国際誌

Kawano H., Ohtani S., Uozumi T., Tokunaga T., Yoshikawa A., Yumoto K., Lucek E.A., André M.

Annales Geophysicae 29 ( 9 ) 1663 - 1672 2011年10月

記述言語：英語掲載種別：研究論文（学術雑誌）

We have analyzed an event on 14 February 2003 in which Cluster satellites and the CPMN ground magnetometer chain made simultaneous observations of a Pi 2 pulsation along the same meridian. Three of the four Cluster satellites were located outside the plasmasphere, while the other one was located within the plasmasphere. By combining the multipoint observations in space and the multipoint observations on the ground, we have obtained a detailed L-profile of the Pi 2 signatures, which has not been done in the past. In addition, we have used a method called Independent Component Analysis (ICA) to separate out other superposed waves with similar spectral components. The result shows that the wave phase of the Pi 2 was the same up to L &sim; 3.9 (corresponding to the plasmasphere), became earlier up to L &sim; 4.1 (corresponding to the plasmapause boundary layer), and showed a delaying tendency up to L &sim; 5.9 (corresponding to the plasmatrough). This systematic phase pattern, obtained for the first time by a combination of a ground magnetometer chain and multisatellites along a magnetic meridian with the aid of ICA, supports the interpretation that a Pi 2 signal propagated from a farther source and reached the plasmasphere. © Author(s) 2011.

DOI： 10.5194/angeo-29-1663-2011

Scopus

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Pi 2 waves simultaneously observed by Cluster and CPMN ground-based magnetometers near the plasmapause 査読有り国際誌

Hideaki Kawano, Shin-ichi Ohtani, Teiji Uozumi, Terumasa Tokunaga, Akimasa Yoshikawa, Kiyohum Yumoto, E. A. Lucek, M. Andre, the CPMN group

Annales Geophysicae ( European Geophysical Union ) 29 ( 9 ) 1663 - 1672 2011年09月

記述言語：英語掲載種別：研究論文（学術雑誌）

We have analyzed an event on 14 February 2003 in which Cluster satellites and the CPMN ground magnetometer chain made simultaneous observations of a Pi 2 pulsation along the same meridian. Three of the four Cluster satellites were located outside the plasmasphere, while the other one was located within the plasmasphere. By combining the multipoint observations in space and the multipoint observations on the ground, we have obtained a detailed L-profile of the Pi 2 signatures, which has not been done in the past. In addition, we have used a method called Independent Component Analysis (ICA) to separate out other superposed waves with similar spectral components. The result shows that the wave phase of the Pi 2 was the same up to L ∼ 3.9 (corresponding to the plasmasphere), became earlier up to L ∼ 4.1 (corresponding to the plasmapause boundary layer), and showed a delaying tendency up to L ∼ 5.9 (corresponding to the plasmatrough). This systematic phase pattern, obtained for the first time by a combination of a ground magnetometer chain and multisatellites along a magnetic meridian with the aid of ICA, supports the interpretation that a Pi 2 signal propagated from a farther source and reached the plasmasphere. © Author(s) 2011.

DOI： https://doi.org/10.5194/angeo-29-1663-2011

STPデータからの異常検出法の開発: Substorm precursor検出への応用

徳永旭将, 中村和幸, 樋口知之, 吉川顕正, 魚住禎司, 池田大輔, 藤本晶子, 森岡昭, 湯元清文, Tokunaga Terumasa, Nakamura Kazuyuki, Higuchi Tomoyuki, Yoshikawa Akimasa, Uozumi Teiji, Ikeda Daisuke, Fujimoto Akiko, Morioka Akira, Yumoto Kiyofumi

宇宙航空研究開発機構特別資料: 第6回「宇宙環境シンポジウム」講演論文集 = JAXA Special Publication: Proceedings of the 6th Spacecraft Enivironment Symposium ( 宇宙航空研究開発機構 ) JAXA-SP-09-006 260 - 265 2010年02月

STPデータからの異常検出法の開発～オーロラサブストームへの応用

徳永旭将

Proceedings of the 6^<th> Space Environment Symposium. 260 - 265 2010年01月

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