セミナーのお知らせ
[MATセミナー開催のお知らせ]
- 開催日時：
- 2021年11月10日(水) 13:00〜15:00
- 使用言語:
- 日本語
- 講演者:
- 髙見英人（数理科学・先端技術研究開発センター）
- タイトル:
- ゲノム情報から生物の生き様を引き出す Genomaple TMシステムについて
- 概要:
-
GenomapleTMは、2018年9月末から横浜研の DAシステムから公開されており、2021年2月末現在での登録ユーザーは45カ国からの323名で、月平均約200ジョブの投入実績を持つシステムです。
GenomapleTMは、ゲノム配列データ(アミノ酸配列データ)があれば特に高度な情報系の知識がなくても簡単に利用できる便利なシステムで、ゲノム・メタゲノム (環境中の網羅的ゲノム)中に見出された遺伝子のアミノ酸配列をKEGGデータベースに参照し、遺伝子IDを割り振り、KEGGが定義した生理・代謝機能遺伝子セット（モジュール）へのマッピングすることで、機能の充足率や機能アバンダンスの計算などが可能です。
また、このシステムを用いることで、個別生物ゲノムやメタゲノムデータから機能遺伝子と生理・代謝情報を結びつけ、生物の機能ポテンシャルを推定、定量化が可能です。これまで、主に微生物ゲノム・メタゲノム解析を中心に利用されてきましたが、大型生物ゲノム解析への応用も可能です。海洋生物のゲノム配列については、まだあまりデータベースに登録されていませんが、容易に生物間や生物群集間での生理・代謝機能の違いを定量的に比較、可視化できます。本セミナーでは、GenomapleTMシステムで何がわかるか？とこれまでの運用実績などについてご紹介します。
以降の講演予定
※タイトル及び概要は決まり次第掲載いたします
[FEAT-MAT合同セミナー開催のお知らせ]
- 開催日時：
- 2021年9月6日(月) 15:00〜16:30
- 使用言語:
- 英語
- 講演者:
- 廣部 紗也子
- タイトル:
- Numerical analysis of dynamic fracture in a residual stress field
- 概要:
- Residual stress field is a self-equilibrated state of stress induced by the inhomogeneous distribution of the inelastic deformations, temperature and moisture gradients or local volume changes due to phase transition. The high level of tensile residual stress often leads to dynamic fracture resulting in the instantaneous and catastrophic destruction of the materials without any persistent external loading. This dynamic fracture in a residual stress field brings substantial theoretical complexity because we have to solve the mutual interaction among crack propagation, change in the residual stress field, and generation of the elastic wave. In this seminar, I will present a mathematical model and a numerical analysis method for dynamic fracture in a residual stress field. We firstly formulate the Hamiltonian for the dynamic behavior of the solid continuum with residual stress field. Introducing the appropriate treatment of the fracture in a residual stress field, this Hamiltonian formulation provides the rigorous evaluation of (i) release and redistribution of the residual stress due to dynamic propagation of the cracks and (ii) the effect of the elastic wave on crack propagation. For evaluating the validity of the proposed mathematical model and numerical analysis method, we performed experiments and numerical analyses of the self-driven fracture process in chemically tempered glass sheets with different residual stress profiles. Our methodology is applicable regardless of materials and scales, ranging from nano crystal glass to earthquake faults.
[MATセミナー開催のお知らせ]
- 開催日時：
- 2021年8月18日(水) 13:00～15:00
- 使用言語:
- 日本語
- 講演者:
- 廣瀬 重信
[MATセミナー開催のお知らせ]
- 開催日時：
- 2021年7月21日(水) 13:00～15:00
- 使用言語:
- 英語
- 講演者:
- Gen Li
[MATセミナー開催のお知らせ]
- 開催日時：
- 2021年7月7日(水) 13:00～15:00
- 使用言語:
- 英語
- 講演者:
- 簑島 敬
[MATセミナー開催のお知らせ]
- 開催日時：
- 2021年6月30日(水) 13:00～15:00
- 使用言語:
- 日本語
- 講演者:
- 大島 逸平（東北大学）
[MATセミナー開催のお知らせ]
- 開催日時：
- 2021年6月23日(水) 13:00～15:00
- 使用言語:
- 英語
- 講演者:
- 丸岡敬和 (生命理工学センター)
[MATセミナー開催のお知らせ]
- 開催日時：
- 2021年6月16日(水) 13:00～15:00
- 使用言語:
- 英語
- 講演者:
- Arthur Bauville
[MATセミナー開催のお知らせ]
- 開催日時：
- 2021年6月9日(水) 13:00〜15:00
- 使用言語:
- 英語
- 講演者:
- Ettore Barbieri
[MATセミナー開催のお知らせ]
- 開催日時：
- 2021年4月28日(水) 13:00〜15:00
- 使用言語:
- 日本語
- 講演者:
- 野口峻佑（環境変動予測研究センター）
- タイトル:
- 太陽からの高エネルギー粒子の降り込みによる成層圏-対流圏結合過程の変調
- 概要:
- 太陽活動変動の地球気候への影響を考えるにあたり、成層圏を介した下方影響過程は重要な役割を担っている。近年、その中でも、太陽高エネルギー粒子の降り込みによる極域上空での化学組成変化の影響が、次第に気候モデルに取り込まれるようになってきており、関心を集めている。本セミナーでは、この過程に関して現在行っている研究を紹介し、皆さんと議論させていただきたい。
[MATセミナー開催のお知らせ]
- 開催日時：
- 2021年4月21日(水) 13:00〜15:00
- 使用言語:
- 英語
- 講演者:
- 髙橋朋子（超先鋭技術開発プログラム）
- タイトル:
- Laser spectroscopic techniques for in-situ chemical measurements of solids in the deep-sea environment
- 概要:
-
Laser spectroscopy is a non-contact, label-free chemical analytical technique, and has a large potential to perform chemical measurements of solid materials such as rocks and particles in-situ in the deep-sea environment. These are typically analysed by sampling-based methods, and in-situ measurement techniques could significantly increase the spatial and temporal resolutions of data acquisition.
In this presentation, the presenter will introduce three laser spectroscopic techniques for in-situ applications, and discuss data interpretation methods:
(i) Particle measurements using holography and laser Raman spectroscopy
By integrating digital holography and laser Raman spectroscopy, morphological and molecular information can be obtained for a floating particle in a large volume of water. Preliminary results of classification of particle types using multivariate analysis and machine learning will be shown.
(ii) Continuous monitoring of microplastics using coherent anti-Stokes Raman scattering (CARS)
Fast chemical imaging of flowing microplastic and bio-organic particles with the size of 20-40μm can be performed by simultaneous detection of CARS and fluorescence. Methods for reconstruction of flowing particle images will be discussed.
(iii) In-situ elemental analysis of hydrothermal deposits using laser induced breakdown spectroscopy
Development and deployments of the deep-sea LIBS anlyser will be introduced. In-situ grid measurement surveys were performed in a hydrothermally active region at the depth more than 1000m, and heavy metals were successfully detected. Quantitative results using partial least squares regression and artificial neural networks will be shown.
[MATセミナー開催のお知らせ]
- 開催日時：
- 2021年3月31日(水) 13:00〜15:00
- 使用言語:
- 英語
- 講演者:
- 野崎達生 (海底資源センター)，北田数也 (超先鋭技術開発プログラム)
- タイトル:
- Long-term monitoring of pressure and temperature of hydrothermal fluid using deep-sea artificial hydrothermal vent and Kuroko-ore cultivation apparatus
- 概要:
-
The IODP Exp. 331 in 2010 drilled the deep-sea active hydrothermal filed at the Iheya-North Knoll, middle Okinawa Trough (Takai et al., 2011, 2012). Due to its drilling operation, four “artificial hydrothermal vents (AHVs)” that were drill holes with hydrothermal fluid discharge were formed. Unnaturally rapid growth of chimney on AHVs inspired us the possibility of the Kuroko-ore (黒鉱; hydrothermal sulfide) cultivation likes as aquafarming (Kawagucci et al., 2013; Nozaki et al., 2016). However, long-term direct measurements targeting the hydrothermal vent and flux data of metal elements which is essential to evaluate the potential of the Kuroko-ore cultivation project are still limited. Thus, during the two drilling cruises performed by using D/V Chikyu in 2016 (cruise CK16-01 and CK16-05), totally three Kuroko-ore cultivation apparatuses were installed at the Original Site of the Iheya-North Knoll (Hole C9024A) and Noho Site of the southern flank of the Iheya Minor Ridge (Holes C9017A and B), middle Okinawa Trough. The Kuroko-ore cultivation apparatus is equipped with two P/T sensors, flowmeter, load cell and their loggers to monitor the pressure, temperature and flow rate of hydrothermal fluid together with the weight of hydrothermal precipitate.
In this seminar, Dr. Nozaki will introduce this project briefly as well as explanations about research purpose, cruise operation, specification of the Kuroko-ore cultivation apparatus and general P/T data of three Kuroko-ore cultivation apparatuses and one flowmeter. Then, Dr. Kitada will do the presentation about detailed analysis about the P/T sensor data equipped with the Kuroko-ore cultivation apparatus at Hole C9017B.
[MATセミナー開催のお知らせ]
- 開催日時：
- 2021年3月24日(水) 13:00〜15:00
- 使用言語:
- 英語
- 講演者:
- 野村 瞬（数理科学・先端技術研究開発センター）
- タイトル:
- My research life in MAT
- 概要:
- In the end of this March, I will leave MAT, JAMSTEC and work in a new affiliation. I introduce the new affiliation from April and explain my motivation in it. Then I will briefly review my research topics, which I fulfilled or completed in JAMSTEC such as theoretical explanation of soil media, experimental investigation of turbidity currents, and exposing test of concrete specimens in the deep sea. After that I will present my research plan which I want to tackle from April. As the latest topics, I will explain the progress the transparent ground technique induced by the refractive index matching and its possibility to extend the field of geoengineering.
[MATセミナー開催のお知らせ]
- 開催日時：
- 2021年2月24日（水）13:00～15:00
- 使用言語:
- 英語
- 講演者:
- 丸岡敬和 (生命理工学センター)
- タイトル:
- The concept of intermediate asymptotics and a dynamical impact of solid sphere onto the PDMS militextured surface
- 概要:
-
In the field of mechanics of continua and soft matter physics, we frequently encounter the mixture of physical properties and the scale-local behavior which changes its scaling relation depending on the spatial and temporal scale. These characters are not only of great interest and attraction, but also the difficulties on the mechanics of continua and soft matter physics. In order to deal with these difficulties, I believe and expect that the concept of intermediate asymptotics, which had been elaborated by G.I. Barenblatt with Ya. B. Zeldovich, would be potentially effective tool. Dimensional analysis extracts the degree of mixture of forces as dimensionless numbers (e.g. Reynolds number are the fraction between inertial force and viscous force), which may be expected to be useful to express the mixing physical properties in soft matter. Scale-local behaviors can be understood as the asymptotic behaviors of global functions, which corresponds to the Barenblatt's formalization of intermediate asymptotics.
In this seminar of first part, I will show the characters of phenomena of soft matter physics briefly and the concept of dimensional analysis and intermediate asymptotics to show the potentiality of their application.
In second part, I will show the application of this idea to the dynamical impact of solid sphere onto the PDMS militextured surface. The crossover of the scaling law between the maximum deformation and the impact velocity was observed in the experiment. I have applied the dimensional analysis to find that the problem belongs to the self-similarity of the second kind. The crossover was explained as the result of the competition between two scaling laws which appears from the expansion of the global dimensionless function, of which each scaling laws can be considered as the intermediate asymptotics.
[MATセミナー開催のお知らせ]
- 開催日時：
- 2021年2月17日（水）13:00～15:00
- 使用言語:
- 英語
- 講演者:
- 日高弥子 (情報エンジニアリングプログラム)
- タイトル:
- Application of deep-learning at JAMSTEC
- 概要:
-
Deep-learning is known as the state-of-the-art underlying technology of AI (Artificial Intelligence). The presenter, who has a background in marine biology, is now involved in some different deep-learning projects, such as super-resolution of bathymetric maps and beached marine litter detection. In this seminar, the presenter will introduce these two topics and the results gained through deep-learning. Any comments and opinions are most welcome.
(1) Super-resolution of bathymetric maps
JAMSTEC launched an interdisciplinary project “mathematical seafloor geomorphology” in 2019. In the project, a technique that can produce high-resolution bathymetric maps from low-resolution maps has been studied. Five deep learning architectures are applied to the same dataset, and the results are compared.
(2) Beached marine litter detection
Beached marine litter is harmful to both finance and the environment. Establishing technologies that can quantify beached marine litter will contribute to mitigation strategies and scientific understanding of the litter. We applied the pixel-wise classification method “semantic segmentation” for beached marine litter estimation. The preliminary results from the study will be introduced.
[MATセミナー開催のお知らせ]
- 開催日時：
- 2021年2月10日（水）13:00～15:00
- 使用言語:
- 日本語
- 講演者:
- 大島逸平 (数理科学・先端技術研究開発センター)
- タイトル:
- 身の回りの微粒化現象とその研究例および今後の展望
- 概要:
- 身の周りの様々な場所において微粒化現象を観測することができる．なかでも，時代の要請により内燃機関内における微粒化現象に着目されがちであった．しかし，微粒化の本質は対象によって何ら変わることはなく，それら研究によって蓄積された技術や知見は様々なところで活用できると考えられる．本セミナーでは，私がこれまで行ってきた研究例だけではなく，これまで様々な研究者によって進められた研究例の一端を紹介し，現状どういった研究開発が可能か，逆に現状何が難しいのか，学会や論文中で紹介されることがない話をしたい．また，今後どういった研究を進めていきたいかなど今後の展望についても紹介しつつ議論する場としたい．
[MATセミナー開催のお知らせ]
- 開催日時：
- 2021年2月3日(水) 13:00 〜 15:00
- 使用言語:
- 日本語
- 講演者:
- 西川 悠 (情報エンジニアリングプログラム)
- タイトル:
- 漁場予測および養殖魚計測に向けた課題と展望
- 概要:
- 漁業には大きく分けて魚を獲りに行く漁獲漁業と魚を育てる養殖漁業があります。ただし現在の日本では、どちらも非常に栄えているとは言い難い状況です。そこで漁獲・養殖漁業を高収益化・効率化する方策として、高解像度海洋モデルに魚の回遊シミュレーションを組み合わせた漁場予測や、バーチャルの養殖生簀と機械学習を用いた養殖魚バイオマスの計測を提案しています。漁場予測は燃油代の削減、養殖魚計測は餌代の削減や自動給餌などに貢献することが期待されます。これらの研究について、現時点での課題や展望についてお話いたします。
[MATセミナー開催のお知らせ]
- 開催日時：
- 2021年1月27日(水) 13:00 〜 15:00
- 使用言語:
- 日本語
- 講演者:
- 河谷 芳雄（環境予測変動研究センター）
- タイトル:
- 温暖化にともなう成層圏大気循環の変化と予測の課題
- 概要:
-
日々の天気の変化が起こる対流圏の上空には，雲のない青々とした成層圏と呼ばれる世界が広がっている．成層圏には，赤道付近で西風と東風が約28ヶ月の周期で交代している準2年振動呼ばれる大規模な振動現象や、赤道から北極・南極へ広がる地球規模の循環がある。観測データ解析や数値実験から地球温暖化の影響は対流圏に留まらず，これら成層圏での大気循環にも及んでいることが分かってきた。本セミナーでは現時点の知見とシミュレーション予測の課題について紹介し、皆さんと議論させていただきたい。
＜概要を日本語で3ページにまとめた記事＞
日本地球惑星科学連合ニュースレター(JGL) vol.16, No.1, P9-11
河谷芳雄，「地球温暖化で成層圏大気の流れが変化」
http://www.jpgu.org/wp-content/uploads/2020/03/JGL_Vol16_1_final.pdf
[MATセミナー開催のお知らせ]
- 開催日時：
- 2021年1月20日(水) 13:00 〜 15:00
- 使用言語:
- 英語
- 講演者1:
- 大河内 直彦 (生物地球化学センター)
- タイトル:
- 生物地球化学って何だ？（What is biogeochemistry?）
- 概要:
-
生物地球化学，生物学と地学と化学が一緒になっていて（物理学はないのか？），いったい何故こんな研究領域があって，どんなことをやっているのか？ ということについて生物地球化学センターの紹介を兼ねて簡潔にまとめる。そのうえで，JAMSTECで取り組んでいるいくつかのトピックについて，ダイジェスト版でおいしいとこ取りをして解説する。
生き物の世界や地球環境の詳しい理解の補助線として，現在行っている方法論開発・機器開発などについても少し触れたい。
数理科学との相性判断についても皆さんと議論できればと考えている。 - 講演者2:
- 磯部 紀之 (生物地球化学センター)
- タイトル:
- Mechanical stress of hydrogel by squeezing or absorbing water
- 概要:
-
Hydrogel is a porous material filled with water. It contains much amount of water (more than 90%) while retaining high integrity. Thanks to these advantages, the hydrogel has been a fascinating material in many applications ranging from biomedicines to foods. For engineering application, the improvement of mechanical property is a major challenge. For this, strengthening the gel matrix (network structure) has been intensively studied, while the effect of water on the mechanical property has rather been underestimated. Here, I show that water can govern the mechanical property of hydrogel based on cellulose (upon squeezing water) and chitin (upon absorbing water).
i) Squeezing water
I reported that a hydrogel made of cellulose can show poroelastic behavior: compressive elastic modulus changes upon the compression speed (Isobe et al. 2018, JTICE). To further understand the poroelastic behavior of cellulose hydrogel, a series of compression tests were performed. Compressive Young's modulus increased up to 4-times larger depending on the compression speed. In addition, the compressive Poisson's ratio, which was calculated from the amount of oozing water, was found to be 0.07, indicating that the horizontal expansion upon vertical compression of the cellulose hydrogel was small. Therefore, it is concluded that the poroelastic response of cellulose hydrogel was given by large amount of water passing through the small pores inside the regenerated cellulose hydrogel.
ii) Absorbing water
Other fascinating property of hydrogel is a volume change induced by external stimuli such as pH, temperature, etc. I found that chitin gel can swell up from the completely dried state by being immersed in acid solution (Isobe et al. 2020, ACS Appl. Polym. Mat.). Swelling materials can serve as a prestressing agent such as expansive cement. To understand the swelling pressure of the chitin hydrogel, here I monitored the time-course change in swelling pressure. Dried chitin hydrogel swelled by the acetic acid solution, and the swelling pressure reached up to 1 MPa in . Moreover, the swelling pressure was kept constant for at least 2 days.
[MATセミナー開催のお知らせ]
- 開催日時：
- 2021年1月13日(水) 13:00 〜 15:00
- 使用言語:
- 英語
- 講演者:
- Patrick Martineau and Ratnam Jayanthi (アプリケーションラボ)
- タイトル:
- Malaria prediction efforts at the application laboratory
- 概要:
-
In this presentation, we are going to report on our progress, ongoing challenges, and future work for the prediction of Malaria in South Africa.
In the first part, we will discuss the development of an early warning malaria prediction framework utilizing machine learning techniques to forecast malaria from observed climate variability. To produce forecasts of malaria incidence with lead times ranging from 3 months to about a year, a set of classifiers are trained on 23 years of historical global climate and South African malaria incidence data to recognize the past influence of climate on the spread of the disease. Through hindcast experiments, we find that the prediction accuracy is adequate during the austral summer when malaria frequency is largest. Among the identified predictors, sea surface temperature variability associated with the El Niño–Southern Oscillation (ENSO) and the Indian Ocean Subtropical Dipole (IOSD) provide an important source of predictability for the classifiers. Challenges associated with the presence of outliers and trends for the identification of useful predictors will be discussed.
In the second part, we are going to discuss the results of a malaria model VECTRI (VECtor borne disease community model of ICTP, TRIeste, Italy), which was used in the project to simulate the number of malaria cases over the north-eastern provinces of South Africa. VECTRI is a dynamical model mimicking the life cycle of malaria and is mainly driven by the climatic parameters, precipitation, and surface air temperature. The model was used to forecast the malaria cases at seasonal time scales using the WRF downscaled SINTEX-F forecasts and also to evaluate the changes in the number of malaria cases over South Africa under the RCP 8.5 climate change scenario by forcing the VECTRI model with the climate change projections of the CORDEX Africa regional model. The results indicate the VECTRI model to be suitable for simulating and predicting the malaria cases over South Africa. However, the model has a bias in simulating a higher number of cases over certain regions of South Africa which needs to be addressed in the future.