Kazuya Okamura

National Institute of Technology, Oshima College

Author Statistics

Papers

Citation

H-Index

i-10 index

Research Trends

Author Order

Document Type

Co-Authors

Ren Saito

Niigata University

Kunihiko Tanaka

Nagaoka University of Technology

Ayaka Kanai

Nagaoka University of Technology

Hirofumi Sakuma

Nichia Corporation (Japan)

Izumi Ojima

Kyoto University

Hayato Saigo

Nagahama Institute of Bio-Science and Technology

Hironori Kitakaze

National Institute of Technology, Oshima College

Ryo Matsumura

National Institute for Materials Science

Takuya Tomono

Nagaoka University of Technology

Tanaka Kunihiko

Nagaoka University

Cooperative Institutions

Nagaoka University

The University of Tokyo

National Institute of Technology, Oshima College

University of Yamanashi

Takeda (Japan)

Nagaoka University of Technology

Osaka Prefecture University College of Technology

Ryukoku University

Tokyo University of Information Sciences

National Institute of Information and Communications Technology

Author Statistics

Papers

Citation

H-Index

i-10 index

Research Field

A two-stage image segmentation method for harvest order decision of wood ear mushroom

Artificial Life and Robotics (2024)

Kazuya Okamura Ryo Matsumura Hironori Kitakaze

10.1007/s10015-024-00971-6

Cite

Citations (0)

Reexamination of the hierarchy problem from a novel geometric perspective

arXiv (Cornell University) (2024)

Hirofumi Sakuma Izumi Ojima Kazuya Okamura

A lucid interpretation of the longstanding hierarchy problem is proposed based on the unconventional model of the universe recently proposed by the authors. Our heuristic cosmological model is developed by considering Penrose and Petit's original ideas as the Weyl curvature hypothesis, conformal cyclic cosmology, and the twin universe model. The uniqueness of our model lies in its incorporation of dark energy and matter, and its single key parameter, adjusted by observational data, is the radius ($R_{dS}$) of a four-dimensional ($4D$) hypersphere called de Sitter space. We presuppose that our $4D$ universe originated from the spontaneous conformal symmetry (SCS) breaking of a light field with a null distance. We show that in this SCS breaking state, the energy--momentum tensor of the space-like electromagnetic field, whose existence is inevitable for quantum electromagnetic field interactions (Greenberg--Robinson theorem), becomes isomorphic to the divergence-free Einstein tensor in the general theory of relativity. Furthermore, we reveal the $R_{dS}$ dependency of the $4D$ gravitational field. Based on these findings, we show an intriguing relation between the magnitude of the gravitational coupling constant and $R_{dS}$. A solution to the hierarchy problem is derived by assuming that $R_{dS}$ depends on the "newly defined cosmological time".

10.48550/arxiv.2406.01626

Cite

Citations (0)

Effect of cover annealing on Cu2SnS3 thin films deposited by dual-source fine-channel mist chemical vapor deposition

Journal of Materials Science Materials in Electronics (2023)

Kunihiko Tanaka Kazuya Okamura Ren Saito Hirotaka Maeta Ayaka Kanai

Monoclinic crystal system

Stoichiometry

10.1007/s10854-023-11155-6

Cite

Citations (1)

Conserved relativistic Ertel's current generating the vortical and thermodynamic aspects of spacetime

arXiv (Cornell University) (2022)

Hirofumi Sakuma Izumi Ojima Hayato Saigo Kazuya Okamura

Motivated by Aoki et al.'s recent research on conserved charges and entropy current, we investigated the conservation of relativistic Ertel's current, which has received little attention outside the field of geophysical fluid dynamics. Ertel's charge is an important indicator of the correlation between vortex vectors and entropy gradient fields in Earth's meridional heat transport. We first show that in the generalized Hamiltonian structure of baroclinic fluids, the duality between the total energy and the Casimir as a function of Ertel's charge plays an important role in the nonrelativistic case. Then, by extending the result to relativistic cases, we show that this finding has far-reaching implications not only for spacetime issues in cosmology but also for the foundation of quantum field theory. An especially important finding is that, as an unreported dual form of the Einstein field equation, we identify a special equation satisfied not only by the vortex tensor field generated by the conserved charge but also by the Weyl tensor in interpreting the physical nature of the metric tensor $g^{μν}$, which appears in the cosmological term $Λg^{μν}$.

10.48550/arxiv.2203.09763

Cite

Citations (0)

Generation of Shubert Calculus Series with Nanometer-scale Photoisomerization in Photochromic Crystal and Double Probe SPM Measurement

The Japan Society of Applied Physics (2019)

Kazuharu Uchiyama Ryo Nakagomi Kazuya Okamura Kingo Uchida Makoto Naruse

Nanometre

Source

Cite

Citations (0)

Screening of Microorganisms Utilizing Glycerol as a Carbon Source for Bio-Fuel Cell System

Journal of Smart Processing (2012)

Motomu Nishioka Ryo IKENAGA Akira OKAI Kazuya Okamura Toru Hidaka

Microorganisms utilizing glycerol as a carbon source were isolated from various soils for glycerol/O2bio-fuel cell system. Among 19 locations at the campus of Osaka Prefecture University Collage of Technology and Uchiagegawa flood-control green space in Neyagawa city, the microorganisms isolated from three points (sample numbers 1-2, 1-3 and 1-8) were able to grow in the medium containing 15% glycerol at 37°C and ones from ten locations could proliferate in the same concentration of glycerol at 25°C. In the case of the microorganisms growing at 37°C, they were similar in appearance and seemed to form biofilm. Among ten isolation bacteria at 25°C, three samples (sample number 2-2, 2-3 and 2-5) showed good proliferation in the condition of 15% glycerol medium. The growth profiles of the microorganism which showed the most significant proliferation (sample number 2-5) were also investigated at various glycerol concentrations, resulting that maximum cell density was suppressed at higher glycerol concentration.

Carbon source

Carbon fibers

Growth medium

10.7791/jspmee.1.99

Cite

Citations (0)

Deposition of Cu-Sn precursors on Mo-coated substrates and preparation of Cu2SnS3 thin films by fine channel mist CVD method

The Japan Society of Applied Physics (2021)

Takuya Tomono Yoshihisa Humitaka Kazuya Okamura Tanaka Kunihiko

Mist

Deposition

Source

Cite

Citations (0)

Fabrication of Cu 2 SnS 3 thin films by dual source fine channel mist CVD method

The Japan Society of Applied Physics (2021)

Kazuya Okamura Takuya Tomono Ren Saito Kunihiko Tanaka

Mist

Source

Cite

Citations (0)

Conserved relativistic Ertel's current generating the vortical and thermodynamic aspects of spacetime

arXiv (Cornell University) (2022)

Hirofumi Sakuma Izumi Ojima Hayato Saigo Kazuya Okamura

Motivated by Aoki et al.'s recent research on conserved charges and entropy current, we investigated the conservation of relativistic Ertel's current, which has received little attention outside the field of geophysical fluid dynamics. Ertel's charge is an important indicator of the correlation between vortex vectors and entropy gradient fields in Earth's meridional heat transport. We first show that in the generalized Hamiltonian structure of baroclinic fluids, the duality between the total energy and the Casimir as a function of Ertel's charge plays an important role in the nonrelativistic case. Then, by extending the result to relativistic cases, we show that this finding has far-reaching implications not only for spacetime issues in cosmology but also for the foundation of quantum field theory. An especially important finding is that, as an unreported dual form of the Einstein field equation, we identify a special equation satisfied not only by the vortex tensor field generated by the conserved charge but also by the Weyl tensor in interpreting the physical nature of the metric tensor $g^{\mu\nu}$, which appears in the cosmological term $\Lambda g^{\mu\nu}$.

Source

Cite

Citations (0)

Preparation of Cu2sns3 Thin Films by Dual-Source Fine Channel Mist Cvd

SSRN Electronic Journal (2022)

Kazuya Okamura Ren Saito Ayaka Kanai Kunihiko Tanaka

Cu 2 SnS 3 (CTS) thin films were prepared by a dual-source mist chemical vapor deposition (CVD) method. Cu-Sn and S mist sources were prepared separately without a vacuum apparatus or using a sulfurization process to reduce costs and to prevent exfoliation of the deposited CTS thin film. The hot plate temperature was varied in the range 350 to 400 °C, and CTS thin films with a suitable morphology for solar cells were produced at 370 °C. However, the composition ratio varied significantly upstream and downstream of the mist flow. Moreover, the S/metal ratio for all obtained films was too low, as a result of a temperature drop due to the low-temperature mist flow. Therefore, the effect of reducing the lift-gas flow rate for the Cu-Sn mist source on the CTS films was investigated to prevent this temperature drop. Samples fabricated with a reduced lift gas flow rate exhibited showed X-ray diffraction peaks attributed to the (200), (131), (-131), and (-333) planes of monoclinic CTS, as well as monoclinic CTS Raman peaks. In addition, the estimated bandgap energy for the CTS thin films was 0.93-0.96 eV, which corresponds to that reported for monoclinic CTS. This indicates that the fabricated samples were monoclinic CTS deposited by dual -source fine channel mist CVD without the need for a sulfurization process.

Mist

10.2139/ssrn.4148142

Cite

Citations (0)