Volume 135
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Seminar Report
Information Theory SG by Dr. Hiroshi Yokota on January 27, 2021
2021-01-28
Today's journal club of the Information Theory Study Group had Hiroshi Yokota (iTHEMS) talk about the replica-permutation method to obtain stable structures. He started off the talk with some introduction of proteins' stable structures. To avoid reaching nonglobally optimal structures, the replica-exchange method used to be applied; however, this method may be computationally expensive and less efficient in some circumstances. Later work has proposed the replica-permutation method by which the candidates of the stable structures are permutated (shuffled) and relaxes the detailed balance condition. He drew an analogy with allocation problems of various volumed cups each filled with water. He finally talked about the application in a paper that examines amyloid ? oligomerization. The audience asked lots of questions about the algorithm per se, physical meaning, and even its potential applications. Thanks, Hiroshi, for the fantastic talk! I as well as arguably all the audience really enjoyed it!
-Ryosuke Iritani (RIKEN iTHEMS)
Journal Club: Sampling the stable structures based on replica-permutation method
January 27 (Wed) at 13:00 - 14:30, 2021
Seminar Report
Biology Seminar by Dr. Takashi Okada on January 21, 2021
2021-01-25
On January 21st, Takashi Okada (RIKEN iTHEMS) gave a talk on Boolean networks at the iTHEMS Biology Seminar. He first introduced the basics of Boolean networks and their applications in Biology, and then talked about his recent work on information transfer in Boolean networks. Network is a theme that is common to almost all fields of Science and is relevant to most of us. Thus, his talk was very useful to get a basic idea of what Boolean network is and how it is applied. Not only the basic introduction, but also his recent work on information transfer was explained very clearly in simple terms, which made it possible for all of us to follow and enjoy. Thanks Takashi!
- Jeffrey Fawcett
Introduction to Boolean modeling and Boolean networks as information processing units
January 21 (Thu) at 10:00 - 11:00, 2021
Upcoming Events
Seminar
iTHEMS Biology Seminar
System identification of mechano-chemical epithelial sheet dynamics
February 4 (Thu) at 10:00 - 11:00, 2021
Yoshifumi Asakura (Ph.D. Student, Graduate School of Biostudies, Kyoto University)
Collective migration of epithelial cells is a fundamental process of multi-cellular organisms. Our recent study using live imaging with FRET-based biosensor discovered that cell migration within an epithelial sheet is oriented by traveling waves of ERK activation. However, it is still elusive how the cells make a decision on migration direction by integrating mechano-chemical signals. Here, we performed reverse-engineering approach to extract a hidden control mechanism in the epithelial sheet dynamics in a data-driven manner. Our model has an ability to forecast cell migration quantified in time-lapse images. Therefore, our approach would be powerful to understand mechano-chemical epithelial sheet dynamics.
Venue: via Zoom
Event Official Language: English
Seminar
iTHEMS Theoretical Physics Seminar
Quantum kinetic theory for chiral and spin transport in relativistic heavy ion collisions and core-collapse supernovae
February 4 (Thu) at 13:00 - 14:30, 2021
Di-Lun Yang (Assistant Professor, Faculty of Science and Technology, Keio University)
Recently, the anomalous transport phenomena of relativistic fermions associated with chirality and spin induced by external fields have been greatly explored in different areas of physics. Notably, such phenomena are in connection to various quantum effects such as quantum anomalies and spin-orbit interaction. The quark gluon plasmas produced from relativistic heavy ion collisions (HIC) and the core-collapse supernovae (CCSN) are both the systems in extreme conditions with high temperature or density and the presence of strong magnetic and vortical fields. Meanwhile, the abundance of light quarks and neutrinos as relativistic fermions created therein accordingly makes these two systems ideal test grounds for studying such exotic transport phenomena. Inversely, the anomalous transport may also give rise to unexpected impacts on the evolution of both systems. However, to analyze such dynamical quantum effects, a novel quantum transport theory delineating the evolution of chirality imbalance and spin has to be introduced. In this talk, I will discuss recent developments and applications of the quantum kinetic theory for chiral and spin transport in the context of HIC and CCSN.
Venue: via Zoom
Event Official Language: English
Workshop
Co-hosted by iTHEMS
The 12th RIKEN-Kyoto University Joint Data Assimilation Workshop
February 10 (Wed) at 13:30 - 16:30, 2021
Language: Japanese/English
Participation deadline: Tuesday, February 9, 2021
Venue: via Online
Event Official Language: Japanese
Seminar
iTHEMS Theoretical Physics Seminar
Quantum mechanical description of energy dissipation and application to heavy-ion fusion reactions
February 16 (Tue) at 13:00 - 14:30, 2021
Masaaki Tokieda (Graduate students, Department of Physics, Tohoku University)
For theoretical description of heavy-ion fusion reactions, two different models have been used depending on the incident energy. At energies above the Coulomb barrier, importance of energy dissipation and fluctuation has been deduced from scattering experiments. To describe them phenomenologically, the classical Langevin equation has successfully been applied. At energies below the Coulomb barrier, on the other hand, the quantum coupled-channels method with a few number of internal states has been applied, and it has succeeded in explaining sub-barrier fusion reactions. While each method succeeds in each energy range, a unified description of heavy-ion fusion reactions from sub-barrier energies to above barrier energies is still missing. To achieve this, we need to treat dissipation and fluctuation quantum mechanically.
In order to describe dissipation and fluctuation quantum mechanically, we have applied ideas of open quantum systems to heavy-ion fusion reactions. I will talk about recent development in this talk. First I will introduce a model Hamiltonian to treat dissipation and fluctuation quantum mechanically, and explain its character and a strategy for numerical studies. I will then apply the model to a fusion problem, and discuss a role of energy dissipation during quantum tunneling. Finally I will discuss a possible future direction for a unified description of heavy-ion fusion reactions.
Venue: via Zoom
Event Official Language: English
Seminar
DMWG Seminar
Mapping the Milky Way by VLBI Astrometry
February 16 (Tue) at 13:30 - 15:00, 2021
Nobuyuki Sakai (Korea Astronomy and Space Science Institute (KASI), Republic of Korea)
Astrometry is the only way to obtain 6D (position-velocity) phase space information for astronomical objects. The unique capability allows us to examine the past, present, and future of the Milky Way.
Firstly, I will introduce history and basics of astrometry. Secondly, I will overview astrometric projects in the world. Thirdly, I will highlight recent astrometric results about the Galactic structure. Lastly, I will introduce astrometric research in Korea as well as future astrometric projects and sciences in 2020s and 30s.
Venue: via Zoom
Event Official Language: English
Conference
Co-hosted by iTHEMS
Blockchain in Kyoto 2021
February 17 (Wed) - 18 (Thu), 2021
Language: Some parts will be in Japanese.
The International Conference on Blockchains and their Applications aims at bringing together researchers and practitioners from various communities of science and technology working on areas related to FinTech, Crypto-asset, and Blockchain.
For more information, please refer to the related links.
Venue: Hybrid Format (International Conference Room I, Clock Tower Centennial Hall, Kyoto University and Online)
Event Official Language: English
Paper of the Week
Week 5 of January
2021-01-28
Title: Drifting Dirac monopole in Berry's phase
Author: Kazuo Fujikawa, Koichiro Umetsu
arXiv: http://arxiv.org/abs/2101.10541v1
Title: Deconfining Phase Boundary of Rapidly Rotating Hot and Dense Matter and Analysis of Moment of Inertia
Author: Yuki Fujimoto, Kenji Fukushima, Yoshimasa Hidaka
arXiv: http://arxiv.org/abs/2101.09173v1
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