Yoshimichi Ohki

Research output

Research output per year 1974 1997 2001 2003 2005 2006 2007 2008 2009 2011 2012 2015 2016 2017 2018 2019 2020 2023

• 391 Article
• 150 Conference contribution
• 89 Paper
• 60 Conference article
• 25 More
  • 11 Comment/debate
  • 6 Review article
  • 4 Short survey
  • 3 Chapter
  • 1 Editorial

Research output per year

Research output per year

Search results

• 2019

  Spatial resolution of a cable fault location attempt by frequency domain reflectometry

  Ohki, Y. & Hirai, N., 2019, p. 845-851. 7 p.

  Research output: Contribution to conference › Paper › peer-review

  • reflectometry 100%
  • Electric fault location 82%
  • cable 73%
  • Cables 57%
  • spatial resolution 55%
  1 Citation (Scopus)
• 2012

  Improvement of inspection and maintenance procedures of polymeric cable insulation used in nuclear power plants in Japan

  Ohki, Y., Hirai, N., Yamamoto, T., Minakawa, T. & Okamoto, T., 2012 Dec 1.

  Research output: Contribution to conference › Paper › peer-review

  • Nuclear power plants 100%
  • Insulation 92%
  • Cables 86%
  • Inspection 81%
  • Fast Fourier transforms 34%
• 2010

  Endurance of polymeric insulating materials in nuclear power plants and needs for condition monitoring of electric cables

  Ohki, Y., Hirai, N., Yamamoto, T., Seguchi, T., Kudoh, H. & Okamoto, T., 2010 Dec 1.

  Research output: Contribution to conference › Paper › peer-review

  • Electric cables 100%
  • Insulating materials 82%
  • Condition monitoring 68%
  • Nuclear power plants 61%
  • Durability 53%
  9 Citations (Scopus)

• Experimental research on the feasibility of biodegradable polymeric insulating materials

  Ohki, Y., Hirai, N., Kaneko, S. & Okabe, S., 2010 Dec 1.

  Research output: Contribution to conference › Paper › peer-review

  • Polybutenes 100%
  • Insulating materials 81%
  • Polycaprolactone 68%
  • Starch 56%
  • Esters 49%
• 2008

  Detection of ion migration in composites for printed circuit boards by the pulsed electroacoustic method

  Natsui, M., Echigo, Y., Tanaka, T., Ohki, Y. & Maeno, T., 2008 Dec 31, p. 376-379. 4 p.

  Research output: Contribution to conference › Paper › peer-review

  • Printed circuit boards 100%
  • Ions 92%
  • Composite materials 58%
  • Composite Material 50%
  • Ion 39%
  8 Citations (Scopus)

• Effects of blending various biodegradable polymer plasticizers on the conduction current and AC breakdown strength in starch ester

  Nemoto, Y., Kato, F., Hirai, N., Ohki, Y., Kaneko, S. & Okabe, S., 2008 Dec 31, p. 542-545. 4 p.

  Research output: Contribution to conference › Paper › peer-review

  • Biodegradable polymers 100%
  • Polybutenes 99%
  • Polycaprolactone 98%
  • Plasticizers 85%
  • Starch 80%
  5 Citations (Scopus)

• Effects of coupling agent and filler dispersion on V-t characteristics of epoxy/silica nanocomposites

  Iizuka, T., Ohki, Y. & Tanaka, T., 2008 Dec 31, p. 60-63. 4 p.

  Research output: Contribution to conference › Paper › peer-review

  • Coupling agents 100%
  • Nanocomposites 81%
  • Silica 78%
  • Fillers 72%
  • Filler 65%
  27 Citations (Scopus)

• High field light emission in LDPE/MgO nanocomposite

  Tanaka, T., Yokoyama, K., Ohki, Y., Murata, Y., Sekiguchi, Y. & Goshowaki, M., 2008 Dec 31, p. 506-509. 4 p.

  Research output: Contribution to conference › Paper › peer-review

  • Light emission 100%
  • Low density polyethylenes 82%
  • Nanocomposites 68%
  • Filler 54%
  • Voltage 46%
  12 Citations (Scopus)

• Material challenge of MgO/LDPE nanocomposite for high field electrical insulation

  Nagao, M., Murakami, Y., Murata, Y., Tanaka, Y., Ohki, Y. & Tanaka, T., 2008 Dec 1.

  Research output: Contribution to conference › Paper › peer-review

  • Low density polyethylenes 100%
  • Nanocomposites 83%
  • Insulation 66%
  • Fillers 65%
  • Insulating materials 32%
  4 Citations (Scopus)

• Nano- and micro-filler combination enabling practical use of nanocomposite insulating materials

  Imai, T., Komiya, G., Murayama, K., Ozaki, T., Sawa, F., Shimizu, T., Harada, M., Ochi, M., Ohki, Y. & Tanaka, T., 2008 Dec 31, p. 299-302. 4 p.

  Research output: Contribution to conference › Paper › peer-review

  • Insulating materials 100%
  • Nanocomposites 85%
  • Fillers 75%
  • Nanocomposite 52%
  • Silica 41%
  8 Citations (Scopus)

• Nanocomposite insulating materials for environmental-conscious heavy electric apparatuses

  Imai, T., Ozaki, T., Sawa, F., Shimizu, T., Harada, M., Ochi, M., Tagami, N., Ohki, Y. & Tanaka, T., 2008 Dec 31. 1 p.

  Research output: Contribution to conference › Paper › peer-review
  1 Citation (Scopus)

• Terahertz dielectric relaxation spectroscopy in polyamide nanocomposite

  Iwai, K., Okada, M., Fuse, N., Ohki, Y., Fukunaga, K. & Mizuno, M., 2008 Dec 31, p. 593-596. 4 p.

  Research output: Contribution to conference › Paper › peer-review

  • Dielectric relaxation 100%
  • Dielectric Relaxation 71%
  • Polymer matrix 70%
  • Polyamides 68%
  • Spectroscopy 64%
• 2006

  Superiority in partial discharge resistance of several polymer nanocomposites

  Tanaka, T., Ohki, Y., Shimizu, T. & Okabe, S., 2006 Dec 1.

  Research output: Contribution to conference › Paper › peer-review

  • Partial discharges 100%
  • Nanocomposites 95%
  • Polymers 65%
  • Fillers 38%
  • Polyamides 19%
  8 Citations (Scopus)
• 2005

  Dipolar polarization and depolarization currents in biodegradable polymers

  Maeno, Y., Kino, H., Omori, S., Hirai, N., Tanaka, T., Ohki, Y., Tajitsu, Y., Kohtoh, M. & Okabe, S., 2005, p. 417-420. 4 p.

  Research output: Contribution to conference › Paper › peer-review
  4 Citations (Scopus)

• Effects of glass transition on the dielectric breakdown and electrical conduction in several biodegradable polymers

  Matsushita, M., Maeno, Y., Kino, H., Fujita, S., Hirai, N., Tanaka, T., Ohki, Y., Tajitsu, Y., Kohtoh, M. & Okabe, S., 2005, p. 413-416. 4 p.

  Research output: Contribution to conference › Paper › peer-review

  • Biodegradable polymers 100%
  • Lactic acid 88%
  • Polyethylene terephthalates 83%
  • Glass transition 73%
  • Electric breakdown 72%
  13 Citations (Scopus)

• Effects of ultraviolet photon irradiation on the space charge accumulation properties of several biodegradable polymers

  Yamaguchi, Y., Hirai, N., Tanaka, T., Ohki, Y., Tajitsu, Y., Kohtoh, M. & Okabe, S., 2005, p. 421-424. 4 p.

  Research output: Contribution to conference › Paper › peer-review

  • Biodegradable polymers 100%
  • Charge distribution 93%
  • Electric space charge 85%
  • Space Charge 82%
  • Photons 76%
  5 Citations (Scopus)

• Effects of water temperature on degradation of several biodegradable polymers immersed in water

  Hirai, N., Tanaka, T., Ohki, Y., Tajitsu, Y., Kohtoh, M. & Okabe, S., 2005, p. 771-774. 4 p.

  Research output: Contribution to conference › Paper › peer-review

  • Biodegradable polymers 100%
  • Succinate 67%
  • Space Charge 55%
  • Degradation 45%
  • Lactic acid 44%
  6 Citations (Scopus)

• Influence of metallic defects on the partial discharges at the interface between epoxy resin and silicone rubber

  Onogi, M., Ohki, Y., Takahashi, T., Takahashi, T. & Okamoto, T., 2005 Jan 1, p. 560-563. 4 p.

  Research output: Contribution to conference › Paper › peer-review

  • Silicone rubber 100%
  • Partial discharges 89%
  • Epoxy resins 86%
  • Epoxy Resin 78%
  • Wire 60%

• Influence of water absorption on charge formation in printed circuit board insulations

  Tanaka, H., Ohki, Y., Fukunaga, K., Maeno, T. & Okamoto, K., 2005 Jan 1, p. 53-56. 4 p.

  Research output: Contribution to conference › Paper › peer-review

  • Space Charge 100%
  • Water absorption 90%
  • Printed circuit boards 77%
  • Electric Field 70%
  • Insulation 67%
  1 Citation (Scopus)

• Irradiation effects on silica glass by ion microbeam for fabrication of optical elements

  Murai, M., Fukagawa, K., Nishikawa, H., Nakamura, T., Ohki, Y., Oikawa, M., Sato, T. & Arakawa, K., 2005, p. 210-213. 4 p.

  Research output: Contribution to conference › Paper › peer-review

  • Fused silica 100%
  • Refractive index 93%
  • Optical devices 92%
  • Irradiation 73%
  • Refractive Index 69%

• Preparation and preliminary characteristic evaluation of epoxy/alumina nanocomposites

  Kozako, M., Yamano, S., Kido, R., Ohki, Y., Kohtoh, M., Okabe, S. & Tanaka, T., 2005, p. 231-234. 4 p.

  Research output: Contribution to conference › Paper › peer-review

  • Nanocomposites 100%
  • Alumina 92%
  • Nanocomposite 61%
  • Partial discharges 41%
  • Permittivity 41%
  51 Citations (Scopus)
• 2003

  Absorption changes induced by UV-photon irradiation in Ge-doped SiO₂ thin films fabricated by plasma CVD method from tetraethoxysilane

  Yanagi, T., Ohki, Y. & Nishikawa, H., 2003 Oct 20, p. 1088-1091. 4 p.

  Research output: Contribution to conference › Paper › peer-review

  • Plasma CVD 100%
  • Light absorption 83%
  • Plasma Chemical Vapour Deposition 74%
  • Photons 65%
  • Photosensitivity 59%

• Effect of an air layer on the insulation performance at the interface between epoxy resin and silicone rubber

  Shibata, K., Ohki, Y., Takahashi, T. & Okamoto, T., 2003 Oct 20, p. 622-625. 4 p.

  Research output: Contribution to conference › Paper › peer-review

  • silicone rubber 100%
  • Soft materials 99%
  • Insulating materials 93%
  • Silicone rubber 92%
  • epoxy resins 80%

• Effect of crosslinking on space charge formation in crosslinked polyethylene

  Hirai, N., Maeno, Y., Tanaka, T., Ohki, Y., Okashita, M. & Maeno, T., 2003, p. 917-920. 4 p.

  Research output: Contribution to conference › Paper › peer-review

  • Electric space charge 100%
  • Space Charge 96%
  • Crosslinking 93%
  • crosslinking 86%
  • Polyethylenes 79%
  13 Citations (Scopus)

• Role of the number of consecutive voltage zero-crossings on the water tree growth in polyethylene

  Kaneko, D., Maeda, T., Ito, T., Ohki, Y., Konishi, T., Nakamichi, Y. & Okashita, M., 2003, p. 932-935. 4 p.

  Research output: Contribution to conference › Paper › peer-review

  • roots of equations 100%
  • Polyethylenes 79%
  • polyethylenes 67%
  • Voltage 54%
  • water 42%
  1 Citation (Scopus)
• 2002

  Interpretation of the relation between residual charge and water trees in XLPE cables

  Hirai, N., Ohki, Y., Takeda, T. & Okamoto, T., 2002 Dec 1, p. 1094-1099. 6 p.

  Research output: Contribution to conference › Paper › peer-review

  • Cables 100%
  • Water 67%
  • Electric fields 28%
  • Electrodes 23%
  • Polyethylenes 16%
  7 Citations (Scopus)
• 2001

  Effect of blending on the dielectric breakdown of polyethylene

  Ono, H., Hirai, N. & Ohki, Y., 2001 Dec 1, p. 574-577. 4 p.

  Research output: Contribution to conference › Paper › peer-review

  • Electric breakdown 100%
  • Polyethylenes 93%
  • Dielectric Material 78%
  • Dielectric Strength 67%
  • Electric space charge 58%
  1 Citation (Scopus)

• Effect of photon irradiation on SBT films

  Ito, T., Nonaka, H., Ohki, Y., Seol, K. S., Choi, I. H. & Kim, Y. T., 2001 Dec 1, p. 661-664. 4 p.

  Research output: Contribution to conference › Paper › peer-review

  • Fluorspar 100%
  • Excimer lasers 93%
  • Surface Damage 91%
  • Perovskite 83%
  • Laser pulses 78%

• Effects of byproducts of dicumyl peroxide on space charge formation in polyethylene

  Hirai, N., Minami, R., Ohki, Y., Okashita, M. & Maeno, T., 2001 Jan 1, p. 450-455. 6 p.

  Research output: Contribution to conference › Paper › peer-review

  • Electric space charge 100%
  • Peroxides 99%
  • Low density polyethylenes 96%
  • Polyethylenes 79%
  • Byproducts 78%
  18 Citations (Scopus)

• Effects of liquid chemicals on space charge evolution in low-density polyethylene

  Minami, R., Hirai, N., Ohki, Y., Okashita, M. & Maeno, T., 2001 Dec 1, p. 87-90. 4 p.

  Research output: Contribution to conference › Paper › peer-review

  • Charge distribution 100%
  • Electric space charge 91%
  • Low density polyethylenes 88%
  • Space Charge 88%
  • Polyethylenes 72%
  8 Citations (Scopus)

• Electrical properties in silicon oxynitride and silicon nitride prepared by plasma-enhanced chemical vapor deposition

  Sato, H., Kato, H., Ohki, Y., Seol, K. S. & Noma, T., 2001 Dec 1, p. 148-151. 4 p.

  Research output: Contribution to conference › Paper › peer-review

  • Plasma enhanced chemical vapor deposition 100%
  • Silicon nitride 85%
  • Plasma Enhanced Chemical Vapour Deposition 84%
  • Electric properties 74%
  • Nitride 68%
  7 Citations (Scopus)

• Fabrication of hafnium silicate films by plasma-enhanced chemical vapor deposition

  Kato, H., Nango, T., Miyagawa, T., Katagiri, T., Ohki, Y., Seol, K. S. & Takiyama, M., 2001 Dec 1, p. 483-486. 4 p.

  Research output: Contribution to conference › Paper › peer-review

  • Hafnium 100%
  • Plasma enhanced chemical vapor deposition 89%
  • Plasma Enhanced Chemical Vapour Deposition 75%
  • Hafnium Atom 75%
  • Silicates 72%
  3 Citations (Scopus)

• On the mechanism of recovery voltage in a dielectric solid proposal of a simple equation

  Yamaguchi, A., Hirai, N. & Ohki, Y., 2001 Dec 1, p. 67-70. 4 p.

  Research output: Contribution to conference › Paper › peer-review

  • Equivalent circuits 100%
  • Dielectric Material 91%
  • Capacitance 88%
  • Voltage 74%
  • Recovery 70%

• Photoluminescence in polymeric insulating materials (low density polyethylene and polypropylene) induced by ultraviolet photons

  Ito, T., Toyoda, T., Hirai, N. & Ohki, Y., 2001 Jan 1, p. 319-323. 5 p.

  Research output: Contribution to conference › Paper › peer-review

  • Photoluminescence 100%
  • Low density polyethylenes 79%
  • Insulating materials 77%
  • Photons 72%
  • Irradiation 63%
  2 Citations (Scopus)

• Photoluminescence properties of hydrogenated amorphous silicon nitride

  Kashio, N., Kato, H., Ohki, Y., Seol, K. S. & Noma, T., 2001 Dec 1, p. 79-82. 4 p.

  Research output: Contribution to conference › Paper › peer-review

  • Photoluminescence 100%
  • Amorphous silicon 84%
  • Amorphous Silicon 83%
  • Silicon nitride 74%
  • Nitride 59%
  2 Citations (Scopus)

• Ultraviolet-photon-induced paramagnetic centers in GE and SN co-doped silica glass

  Fujimaki, M., Tokuhiro, S. I., Nakanishi, T., Nomura, K. I., Ohki, Y. & Imamura, K., 2001 Dec 1, p. 665-668. 4 p.

  Research output: Contribution to conference › Paper › peer-review

  • Excimer lasers 100%
  • Absorption spectra 94%
  • Fused silica 90%
  • Paramagnetic Center 87%
  • Photons 76%
• 2000

  Electroluminescence in silicon oxynitride

  Kato, H., Masuzawa, A., Sato, H., Ohki, Y., Fujimaki, M., Seol, K. S. & Noma, T., 2000 Dec 1, p. 402-406. 5 p.

  Research output: Contribution to conference › Paper › peer-review

  • Electroluminescence 100%
  • oxynitrides 75%
  • electroluminescence 64%
  • Silicon 49%
  • Photoluminescence 41%
  1 Citation (Scopus)

• Photoluminescence in polypropylene induced by ultraviolet laser irradiation

  Ohki, Y., Toyoda, T., Hama, Y., Wei, W. & Massines, F., 2000 Dec 1, p. 439-442. 4 p.

  Research output: Contribution to conference › Paper › peer-review

  • Ultraviolet lasers 100%
  • Photoluminescence 91%
  • Laser beam effects 84%
  • Luminescence 83%
  • ultraviolet lasers 59%
  3 Citations (Scopus)
• 1998

  Dielectric breakdown in F-doped SiO₂ films formed by plasma-enhanced chemical vapor deposition

  Kato, H., Sakai, S., Takami, A., Ohki, Y. & Ishii, K., 1998 Dec 1, p. 368-371. 4 p.

  Research output: Contribution to conference › Paper › peer-review

  • Plasma enhanced chemical vapor deposition 100%
  • Fluorine 97%
  • Electric breakdown 79%
  • Silica 36%
  • Polymers 25%

• Dielectric properties of new-type polyethylene polymerized using a single-site catalyst

  Araoka, M., Yoneda, H. & Ohki, Y., 1998 Dec 1, p. 493-494. 2 p.

  Research output: Contribution to conference › Paper › peer-review

  • Dielectric properties 100%
  • Polyethylenes 87%
  • Catalysts 69%
  • Linear low density polyethylenes 58%
  • Low density polyethylenes 52%
  3 Citations (Scopus)

• Effect of acetophenone on space charge formation in LDPE and LLDPE

  Ohara, T., Kobayashi, K., Ohki, Y. & Maeno, T., 1998 Dec 1, p. 231-234. 4 p.

  Research output: Contribution to conference › Paper › peer-review

  • Linear low density polyethylenes 100%
  • Electric space charge 93%
  • Low density polyethylenes 90%
  • Space Charge 89%
  • Acetophenone 75%

• Effect of ozone annealing on the charge trapping property of Ta₂O₅-Si₃N₄-p-Si capacitor grown by low pressure chemical vapor deposition

  Kato, H., Seol, K. S., Toyoda, T. & Ohki, Y., 1998 Dec 1, p. 131-134. 4 p.

  Research output: Contribution to conference › Paper › peer-review

  • Low pressure chemical vapor deposition 100%
  • Charge trapping 96%
  • Low Pressure Chemical Vapour Deposition 89%
  • Ozone 77%
  • Capacitor 62%
  2 Citations (Scopus)

• Effects of ion implantation and thermal annealing on the photoluminescence in amorphous silicon nitride films

  Seol, K. S., Futami, T., Watanabe, T., Ohki, Y. & Takiyama, M., 1998 Dec 1, p. 127-130. 4 p.

  Research output: Contribution to conference › Paper › peer-review

  • Photoluminescence 100%
  • Amorphous silicon 84%
  • Amorphous Silicon 83%
  • Ion implantation 83%
  • Ion Implantation 75%

• Electrical properties of thermoplastic polyimide

  Takei, S., Tanabe, Y. & Ohki, Y., 1998 Dec 1, p. 349-350. 2 p.

  Research output: Contribution to conference › Paper › peer-review

  • Polyimides 100%
  • Electric properties 90%
  • Thermoplastics 85%
  • Impurities 82%
  • Hot Temperature 40%
  2 Citations (Scopus)

• Photoluminescence and electron-spin-resonance studies of defects in amorphous SiO₂ films

  Nishikawa, H., Fukui, H., Watanabe, E., Ito, D., Seol, K. S. & Ohki, Y., 1998 Dec 1, p. 59-62. 4 p.

  Research output: Contribution to conference › Paper › peer-review

  • Photoluminescence 100%
  • Plasma enhanced chemical vapor deposition 87%
  • Paramagnetic resonance 83%
  • Plasma Enhanced Chemical Vapour Deposition 74%
  • Oxygen 49%

• Structural changes in Ge-doped SiO₂ planar waveguides induced by ultraviolet photons

  Shimoto, S., Fujimaki, M., Miyazaki, N., Nishihara, Y., Ohki, Y., Imamura, K. & Terasawa, K., 1998 Dec 1, p. 47-50. 4 p.

  Research output: Contribution to conference › Paper › peer-review

  • Planar waveguides 100%
  • Photons 75%
  • Chemical vapor deposition 74%
  • Photon 61%
  • Paramagnetic Center 57%
• 1997

  Effect of γ-ray irradiation on the thermally stimulated current in polyethersulfone

  Ohki, Y., Kim, E., Kato, G. & Ohara, T., 1997 Jan 1, p. 798-801. 4 p.

  Research output: Contribution to conference › Paper › peer-review

  • Thermally Stimulated Current 100%
  • Poly(ether-Sulfone) Polymer 75%
  • Irradiation 63%
  • rays 53%
  • Dose 47%
• 1996

  Dielectric breakdown properties of low-density polyethylene under power-frequency voltages with high-frequency components

  Suzuki, H., Ohki, Y., Nakamichi, Y. & Ajiki, K., 1996 Dec 1, p. 203-206. 4 p.

  Research output: Contribution to conference › Paper › peer-review

  • Low density polyethylenes 100%
  • Electric breakdown 87%
  • Electric potential 40%
  • Cables 31%
  • Polymers 28%

• Energy distribution of traps in polyethersulfone film estimated through surface potential measurements

  Li, S., Xie, H. & Ohki, Y., 1996 Dec 1, p. 113-116. 4 p.

  Research output: Contribution to conference › Paper › peer-review

  • Surface potential 100%
  • Polymers 26%
  3 Citations (Scopus)

• Experimental observation and numerical calculation of space charge formation in gamma-irradiated polyethylene

  Takada, T., Kitajima, H., Tanaka, Y. & Ohki, Y., 1996 Dec 1, p. 105-108. 4 p.

  Research output: Contribution to conference › Paper › peer-review

  • Electric space charge 100%
  • Polyethylenes 79%
  • Low density polyethylenes 77%
  • Charge distribution 65%
  • Electrons 45%
  1 Citation (Scopus)