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Hybridization of colloidal handlebodies with singular defects and topological solitons in chiral liquid crystals

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arXiv 2025年

作者： Lee, Jun-Yong Kumari, Asha Yuan, Ye Tasinkevych, Mykola Smalyukh, Ivan I. International Institute for Sustainability with Knotted Chiral Meta Matter Hiroshima University 1-3-1 Kagamiyama Higashi-Hiroshima Hiroshima739-8526 Japan Department of Physics and Mathematics School of Science and Technology Nottingham Trent University Clifton Lane NottinghamNG11 8NS United Kingdom Department of Physics University of Colorado BoulderCO80309 United States Department of Electrical Computer and Energy Engineering Materials Science and Engineering Program and Soft Materials Research Center University of Colorado BoulderCO80309 United States Renewable and Sustainable Energy Institute National Renewable Energy Laboratory University of Colorado BoulderCO80309 United States

Topology can manifest itself in colloids when quantified by invariants like Euler characteristics of nonzero-genus colloidal surfaces, albeit spherical colloidal particles are most often studied, and colloidal particles with complex topology are rarely considered. On the other hand, singular defects and topological solitons often define the physical behavior of the molecular alignment director fields in liquid crystals. Interestingly, nematic liquid crystalline dispersions of colloidal particles allow for probing the interplay between topologies of surfaces and fields, but only a limited number of such cases have been explored so far. Here, we study the hybridization of topological solitons, singular defects, and topologically nontrivial colloidal particles with the genus of surfaces different from zero in a chiral nematic liquid crystal phase. Hybridization occurs when distortions separately induced by colloidal particles and LC solitons overlap, leading to energy minimization-driven redistribution of director field deformations and defects. As a result, hybrid director configurations emerge, combining topological features from both components. We uncover a host of director field configurations complying with topological theorems, which can be controlled by applying electric fields. Rotational and translational dynamics arise due to the nonreciprocal evolution of the director fields in response to alternating electric fields of different frequencies. These findings help define a platform for controlling topologically hyper-complex colloidal structures and dynamics with electrically reconfigurable singular defects and topological solitons induced by colloidal handlebodies. Copyright © 2025, The Authors. All rights reserved.

关键词： Topology

Progress in wearable electronics/photonics—Moving toward the era of artificial intelligence and internet of things

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InfoMat 2020年第6期2卷 1131-1162页

作者： Qiongfeng Shi Bowei Dong Tianyiyi He Zhongda Sun Jianxiong Zhu Zixuan Zhang Chengkuo Lee Department of Electrical and Computer Engineering National University of SingaporeSingapore117576Singapore Center for Intelligent Sensors and MEMS National University of SingaporeSingapore117608Singapore Hybrid-Integrated Flexible(Stretchable)Electronic Systems Program National University of SingaporeSingapore117608Singapore NUS Suzhou Research Institute(NUSRI) Suzhou215123China NUS Graduate School for Integrative Science and Engineering National University of SingaporeSingapore117456Singapore

The past few years have witnessed the significant impacts of wearable electronics/photonics on various aspects of our daily life,for example,healthcare monitoring and treatment,ambient monitoring,soft robotics,prosthetics,flexible display,communication,human-machine interactions,and so *** to the development in recent years,the next-generation wearable electronics and photonics are advancing rapidly toward the era of artificial intelligence(AI)and internet of things(IoT),to achieve a higher level of comfort,convenience,connection,and ***,this review provides an opportune overview of the recent progress in wearable electronics,photonics,and systems,in terms of emerging materials,transducing mechanisms,structural configurations,applications,and their further integration with other ***,development of general wearable electronics and photonics is summarized for the applications of physical sensing,chemical sensing,humanmachine interaction,display,communication,and so *** self-sustainable wearable electronics/photonics and systems are discussed based on system integration with energy harvesting and storage ***,technology fusion of wearable systems and AI is reviewed,showing the emergence and rapid development of intelligent/smart *** the last section of this review,perspectives about the future development trends of the next-generation wearable electronics/photonics are provided,that is,toward multifunctional,self-sustainable,and intelligent wearable systems in the AI/IoT era.

关键词： artificial intelligence energy harvesting human-machine interface internet of things wearable electronics wearable photonics

Achieving covertness and secrecy: A new paradigm for secure wireless communication

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arXiv 2020年

作者： Wu, Huihui Zhang, Yuanyu Shen, Yulong Jiang, Xiaohong The School of Computer Science and Technology Xidian University Xi'an Shaanxi China The School of Systems Information Science Future University Hakodate Hakodate Hokkaido Japan The Graduate School of Science and Technology Nara Institute of Science and Technology 8916-5 Takayama Ikoma Nara630-0192 Japan

This paper explores a new secure wireless communication paradigm where the physical layer security technology is applied to counteract both the detection and eavesdropping attacks, such that the critical covertness and secrecy properties of the communication are jointly guaranteed. We first provide theoretical modeling for covertness outage probability (COP), secrecy outage probability (SOP) and transmission probability (TP) to depict the covertness, secrecy and transmission performances of the paradigm. To understand the fundamental security performance under the new paradigm, we then define a new metric - covert secrecy rate (CSR), which characterizes the maximum transmission rate subject to the constraints of COP, SOP and TP. We further conduct detailed theoretical analysis to identify the CSR under various scenarios determined by the detector-eavesdropper relationships and the secure transmission schemes adopted by transmitters. Finally, numerical results are provided to illustrate the achievable performances under the new secure communication paradigm. Copyright © 2020, The Authors. All rights reserved.

关键词： Probability

Evaluation of real robot agent interface for spoken dialogue system 8

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Evaluation of real robot agent interface for spoken dialogue...

8th IEEE Global Conference on Consumer Electronics, GCCE 2019

作者： Yamamoto, Kazumasa Tamagawa, Akira Nakagawa, Seiichi Chubu University Dept. Computer Science Kasugai Japan Graduate School of Engineering Toyohashi University of Technology Toyohashi Japan

ISBN: (纸本)9781728135755

The talk target of spoken dialogue system can be 'a robot (real)' or 'a screen agent (virtual person / living thing)'. When considering from the viewpoint of easy-to-talk and familiarity, the physical robot could be better because of its physical characteristics. In this research, we constructed a dialogue system with the pet robot 'Phyno', which is a friendly interface as a talk partner, and conducted evaluation experiments compared with a display agent interface in a monitor display or personal data assistant. The experimental results show the benefits of the robot's physicality. © 2019 IEEE.

关键词： Robots

Mesenchymal stromal cell exosomes enhance dental pulp cell functions and promote pulp-dentin regeneration

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Biomaterials and Biosystems 2023年 11卷

作者： Shi, Jiajun Teo, Kristeen Ye Wen Zhang, Shipin Lai, Ruenn Chai Rosa, Vinicius Tong, Huei Jinn Duggal, Mandeep S. Lim, Sai Kiang Toh, Wei Seong Faculty of Dentistry National University of Singapore Singapore Institute of Molecular and Cell Biology Agency for Science Technology and Research Singapore Oral Care Health Innovations and Designs Singapore National University of Singapore Singapore College of Dental Medicine QU Health Qatar University Qatar Department of Orthopaedic Surgery Yong Loo Lin School of Medicine National University of Singapore Singapore Department of Biomedical Engineering Faculty of Engineering National University of Singapore Singapore Tissue Engineering Program Life Sciences Institute National University of Singapore Singapore Integrative Sciences and Engineering Program NUS Graduate School National University of Singapore Singapore

Mesenchymal stromal/stem cell (MSC) therapies are currently being explored for dental pulp regeneration. As the therapeutic effects of MSCs in tissue repair are mediated mainly through the release of extracellular vesicles (EVs) including exosomes, we investigated here the cellular processes and molecular mechanisms modulated by MSC exosomes in dental pulp regeneration. Using dental pulp cell (DPC) cultures, we demonstrated that MSC exosomes could increase DPC migration, proliferation, and odontogenic differentiation. The enhancement of these cellular processes was mediated through exosomal CD73-mediated adenosine receptor activation of AKT and ERK signaling. Consistent with these observations, MSC exosomes increased the expression of dentin matrix proteins and promoted the formation of dentin-like tissue and bridge-like structures in a rat pulp defect model. These effects were comparable to that of mineral trioxide aggregate (MTA) treatment. MSC exosomes also yielded recellularized pulp-dentin tissues in the root canal of endodontically-treated human premolars, following subcutaneous implantation in the mouse dorsum. Together, our findings suggest that MSC exosomes could exert a multi-faceted effect on DPC functions including migration, proliferation and odontogenic differentiation to promote dental pulp regeneration. This study provides the basis for development of MSC exosomes as a cell-free MSC therapeutic alternative for pulp-dentin regeneration. © 2023

关键词： Dental pulp Exosomes Extracellular vesicles Mesenchymal stromal/stem cells Regeneration

Secure millimeter-wave Ad Hoc communications using physical layer security

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arXiv 2020年

作者： Zhang, Yuanyu Shen, Yulong Jiang, Xiaohong Kasahara, Shoji Graduate School of Science and Technology Nara Institute of Science and Technology 8916-5 Takayama Ikoma Nara630-0192 Japan School of Computer Science and Technology Xidian University Xi’an Shaanxi China School of Systems Information Science Future University Hakodate HakodateHokkaido Japan

Millimeter-wave (mmWave) communications are highly promising to improve the capacity of modern wireless networks, while the physical layer security (PLS) techniques hold great potential to enhance the critical secrecy performance therein. By carefully exploiting the significant signal difference between the Non-Light-of-Sight (NLoS) and Line-of-Sight (LoS) mmWave links, this paper proposes a Sight-based Cooperative Jamming (SCJ) scheme to improve the PLS performance of mmWave ad hoc communications. In this scheme, each potential jammer that has no LoS link to its nearest receiver but may have LoS links to eavesdroppers is selected with a certain probability to generate artificial noise such that channel advantages at legitimate receivers can be achieved. For performance modeling of the new jamming scheme, novel and efficient theoretical approximation approaches are firstly developed to enable the challenging issue of interference distribution modeling to be tackled, and then a theoretical framework based on stochastic geometry is proposed to capture the secrecy transmission capacity behavior under the SCJ scheme. Finally, extensive numerical results are provided to illustrate the SCJ scheme under various network scenarios. Copyright © 2020, The Authors. All rights reserved.

关键词： Millimeter waves

Analysis of temporal structure of laser chaos by Allan variance

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arXiv 2022年

作者： Asuke, Naoki Chauvet, Nicolas Röhm, André Kanno, Kazutaka Uchida, Atsushi Niiyama, Tomoaki Sunada, Satoshi Horisaki, Ryoichi Naruse, Makoto Department of Information Physics and Computing Graduate School of Information Science and Technology The University of Tokyo 7-3-1 Hongo Bunkyo-ku Tokyo113-8656 Japan Department of Information and Computer Sciences Saitama University 255 Shimo-Okubo Sakura-ku Saitama Saitama City338-8570 Japan Faculty of Mechanical Engineering Institute of Science and Engineering Kanazawa University Kakuma Ishikawa Kanazawa920-1192 Japan

Allan variance has been widely utilized in evaluating the stability of the time series generated by atomic clocks and lasers, in time regimes ranging from short to extremely long. This multi-scale examination capability of the Allan variance may also be beneficial in evaluating the chaotic oscillating dynamics of semiconductor lasers, not just for conventional phase stability analysis purposes. Here we demonstrate Allan variance analysis of the complex time series generated by a semiconductor laser with delayed feedback, including low-frequency fluctuations (LFFs), which exhibit both fast and slow dynamics. Whereas the detection of LFFs is not easy with the conventional power spectrum analysis method in the low-frequency regime, we show that the Allan variance approach clearly captured the appearance of multiple time-scale dynamics, like LFFs. This study demonstrates that Allan variance can help in understanding and characterizing versatile laser dynamics, including LFFs, which involve dynamics spanning a wide range of time scales. Copyright © 2022, The Authors. All rights reserved.

关键词： Semiconductor lasers

Disentanglement of intrinsic and extrinsic side-jump scattering induced spin Hall effect in N-implanted Pt

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arXiv 2022年

作者： Shashank, Utkarsh Nakamura, Yoji Kusaba, Yu Tomoda, Takafumi Nongjai, Razia Kandasami, Asokan Medwal, Rohit Rawat, Rajdeep Singh Asada, Hironori Gupta, Surbhi Fukuma, Yasuhiro Department of Physics and Information Technology Faculty of Computer Science and Systems Engineering Kyushu Institute of Technology 680-4 Kawazu Iizuka820-8502 Japan Materials Science Division Inter University Accelerator Centre Aruna Asaf Ali Marg New Delhi110067 India Uttarakhand Dehradun248007 India Department of Physics Indian Institute of Technology Kanpur Kanpur208016 India Natural Sciences and Science Education National Institute of Education Nanyang Technological University 637616 Singapore Graduate School of Sciences and Technology for Innovation Yamaguchi University 2-16-1 Tokiwadai Ube755-8611 Japan Research Center for Neuromorphic AI hardware Kyushu Institute of Technology Kitakyushu808-0196 Japan

The rapidly evolving utilization of spin Hall effect (SHE) arising from spin-orbit coupling in 5d transition metals and alloys have made giant strides in the development of designing low-power, robust and non-volatile magnetic memory. Recent studies, on incorporating non-metallic lighter elements such as oxygen, nitrogen and sulfur into 5d transition metals, have shown an enhancement in damping-like torque efficiency θDL due to the modified SHE, but the mechanism behind this enhancement is not clear. In this paper, we study θDL at different temperatures (100-293 K) to disentangle the intrinsic and extrinsic side-jump scattering induced spin Hall effect in N-implanted Pt. We observe a crossover of intrinsic to extrinsic side-jump mechanism as the implantation dose increases from 2×1016 ions/cm2 to 1×1017 ions/cm2. A sudden decrease in the intrinsic spin Hall conductivity is counterbalanced by the increase in the side-jump induced SHE efficiency. These results conclude that studying θDL as a function of implantation dose, and also as a function of temperature, is important to understand the physical mechanism contributing to SHE, which has so far been unexplored in incorporating non-metallic element in 5d transition metals. Copyright © 2022, The Authors. All rights reserved.

关键词： Spin Hall effect

Transition probabilities of near-infrared Ce III lines from stellar spectra: applications to kilonovae

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arXiv 2023年

作者： Domoto, Nanae Lee, Jae-Joon Tanaka, Masaomi Lee, Ho-Gyu Aoki, Wako Ishigaki, Miho N. Wanajo, Shinya Kato, Daiji Hotokezaka, Kenta Astronomical Institute Tohoku University Aoba Sendai980-8578 Japan Korea Astronomy and Space Science Institute 776 Daedeok-daero Yuseong-gu Daejeon34055 Korea Republic of Division for the Establishment of Frontier Sciences Organization for Advanced Studies Tohoku University Sendai980-8577 Japan Space Policy Research Center Science and Technology Policy Institute 370 Sicheong-daero Sejong30147 Korea Republic of National Astronomical Observatory 2-21-1 Osawa Mitaka Tokyo181-8588 Japan Astronomical Science Program The Graduate University for Advanced Studies SOKENDAI 2-21-1 Osawa Mitaka Tokyo181-8588 Japan Am Mühlenberg 1 Potsdam-GolmD-14476 Germany RIKEN Saitama Wako351-0198 Japan National Institute for Fusion Science 322-6 Oroshi-cho Toki509-5292 Japan Interdisciplinary Graduate School of Engineering Sciences Kyushu University Fukuoka Kasuga816-8580 Japan Research Center for the Early Universe Graduate School of Science University of Tokyo Tokyo Bunkyo113-0033 Japan UTIAS The University of Tokyo Chiba Kashiwa277-8583 Japan

Kilonova spectra provide us with information of r-process nucleosynthesis in neutron star mergers. However, it is still challenging to identify individual elements in the spectra mainly due to lack of experimentally accurate atomic data for heavy elements in the near-infrared wavelengths. Recently, Domoto et al. (2022) proposed the absorption features around 14500 Å in the observed spectra of GW170817/AT2017gfo as Ce III lines. But they used theoretical transition probabilities (gf-values) whose accuracy is uncertain. In this paper, we derive the astrophysical gf-values of the three Ce III lines, aiming at verification of this identification. We model high resolution H-band spectra of four F-type supergiants showing the clear Ce III absorption features by assuming stellar parameters derived from optical spectra in literatures. We also test the validity of the derived astrophysical gf-values by estimating Ce III abundances in Ap stars. We find that the derived astrophysical gf-values of the Ce III lines are systematically lower by about 0.25 dex than those used in previous work of kilonovae, while they are still compatible within the uncertainty range. By performing radiative transfer simulations of kilonovae with the derived gf-values, we find that the identification of Ce III as a source of the absorption features in the observed kilonova spectra still stands, even considering the uncertainties in the astrophysical gf-values. This supports identification of Ce in the spectra of GW170817/AT2017gfo. © 2023, CC BY.

关键词： Stars