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Yoshiki Hidaka Last modified date:2020.06.22



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Homepage
https://kyushu-u.pure.elsevier.com/en/persons/�F��-��
 Reseacher Profiling Tool Kyushu University Pure
http://www.hidaka.ap.kyushu-u.ac.jp/en/index-e.html
Academic Degree
Doctor of Engineering
Country of degree conferring institution (Overseas)
No
Field of Specialization
Nonlinear Physics
Total Priod of education and research career in the foreign country
00years00months
Outline Activities
Nonlinear physics of dissipative structure and weak turbulence using liquid crystals

Department of Applied Quantum Physics and Nuclear Engineering, Graduate School of Engineering
Department of Energy Science and Engineering, Faculty of Engineering
Research
Research Interests
  • Study on Connective Phenomena in Porous Media using Polymer–Liquid Crystal Composite Systems
    keyword : Convection, Nematic Electroconvection, Polymer Network, Porous Media
    2018.04.
  • Diffusion in Defect Turbulence
    keyword : defect turbulecnce, spatiotemporal chaos, abnormal diffusion
    2009.04Diffusion Phenomenon in Soft-Mode Turbulence.
  • Magnetic Field Response of Soft-Mode Turbulence
    keyword : soft-mode turbulence, response
    2008.07.
  • Diffusion Phenomena in Spatiotemporal Intermittency
    keyword : spatiotemporal intermittency, diffusion, Brownian motion
    2009.07.
  • Statistical Properties of Spatiotemporal Chaos in Electroconvection of Nematics
    keyword : spatiotemporal chaos, statistical mechanics
    2006.04Statistical Properties of Spatiotemporal Chaos.
  • Controlling of Spatiotemporal Chaos in Electroconvection of Nematics
    keyword : spatiotemporal intermittency, controlling chaos
    2004.01Control of Spatiotemporal Chaos in Electroconvection of Nematics.
  • Spatial Structures of Soft-Mode Turbulence
    keyword : soft-mode turbulence, spatiotemporal chaos
    2002.05Spatial Structure of Soft-Mode Turbulence.
  • Formation Mechanism of Defect Lattice in Electroconvection of Nematics
    keyword : pattern formation, spatiotemporal chaos
    2002.01~2004.12Formation Mechanism of Defect Lattice in Electroconvection of Nematics.
  • Diffusion in Soft-Mode Turbulence
    keyword : soft-mode turbulecnce, spatiotemporal chaos, abnormal diffusion
    2000.04Diffusion Phenomenon in Soft-Mode Turbulence.
  • Formation Process and Dynamics of Grid Pattern in Electroconvection of Nematics
    keyword : pattern formation, defect turbulence, grid pattern
    2003.05~2004.03Formation Process and Dynamics of Grid Pattern in Electroconvection of Nematics.
  • Formation Mechanism of Prewavy Pattern in Nematic Liquid Crystal
    keyword : nematic liquid crystal, pattern formation
    1999.04~2003.03Formation Mechanism of Prewavy Pattern in Nematic Liquid Crystal.
Academic Activities
Reports
1. Pattern Formation in Liquid Crystals
Yoshiki HIDAKA and Shoichi KAI
Ekisho, Vol. 4, No. 3, pp.219-234 (2000).
Papers
1. Noriko Oikawa, Tomohiro Gunji, and Yoshiki Hidaka, Grid pattern emerging from complex dynamics of defects, Physical Review E, 10.1103/PhysRevE.101.062204, 101, 062204-1-062204-7, 2020.06, The formation process and growth dynamics of the grid pattern, a cellular convective pattern in the electroconvection of nematic liquid crystals, are investigated. The grid pattern appears via a disordered state called defect turbulence with the increasing of an applied voltage. The averaged defect density increases with the applied voltage and then the defects that have been in the continuous process of creation and annihilation are frozen as grid cells forming domain structures. The area fraction of the grid domains is adopted as the order parameter. The temporal growth of the area fraction for the step voltage was also measured. By applying the Kolmogorov-Avrami model to the results, it is suggested that the growth dynamics of the grid domain is not primarily governed by domain growth, but by the local transition of the rolls to the cellular flow via preliminary grid structures that transiently appear..
2. Misatao Iino, Yoshiki Hidaka, Hirotaka Okabe, Kazuhiro Hara, Responses of spatiotemporal chaos to oscillating forces, Physical Review E, 0.1103/PhysRevE.92.012916, 92, 012916-1-042147-5, 2015.07, The responses of soft-mode turbulence, a kind of spatiotemporal chaos seen in electroconvection of a nematic liquid crystal, to alternating-current magnetic fields is investigated to uncover the dynamical properties of spatiotemporal chaos. The dynamical responses can be measured by an order parameter, Mp(t), which indicates ordering in the convective roll pattern induced by the magnetic field. Determined by properties of the liquid crystal in a magnetic field, Mp(t) oscillates in accordance with the square of the magnetic field. The relaxation time of the system was obtained by fitting the frequency dependence of the complex susceptibility for the pattern obtained from the oscillation of Mp(t) to the Debye-type relaxation spectra. However, for the high-frequency regime, the susceptibility deviates from the spectra because slow and large fluctuations of Mp(t) contribute to the oscillation. The properties of this type of fluctuation were investigated by introducing a dynamic ordering parameter defined as the period average of Mp(t)..
3. Yoshiki HIDAKA, Yusaku HOSOKAWA, Noriko OIKAWA, Koyo TAMURA, Rinto ANUGRAHA, Shoichi KAI, A nonequilibrium temperature and fluctuation theorem for soft-mode turbulence, Physica D, 239, 11, 735-738, 2010.06.
4. Yoshiki HIDAKA, Koyo TAMURA and Shoichi KAI, Soft-Mode Turbulence in Electroconvection of Nematics, Progress of Theoretical Physics Supplement, No. 161, pp. 1-11, 2006.01.
Presentations
1. On Soft-Mode Turbulence.
2. Chevron-Wavy Pattern in Liquid Crystals
Yoshiki HIDAKA
RIMS Project 2000 "Reaction-diffusion systems: theory and applications" Interfaces, Pulses and Waves in Nonlinear Dissipative Systems.
3. Prewavy : A Director-Modulation Pattern in Nematic Liquid Crystals
Jong-Hoon HUH, Yoshiki HIDAKA, Yusril YUSUF, N?ndor ?BER, Tibor T?tH-KATONA, ?gnes BUKA and Shoichi KAI
18th International Liquid Crystal Conference (ILCC2000).
Educational
Educational Activities
Department of Applied Quantum Physics and Nuclear Engineeing
Department of Energy Science and Engineering