result 1447 件
| JaLCDOI | 10.18926/19673 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_33_2_61.pdf |
| Author | Totsuji, Hiroo| Tsuruta, Kenji| Totsuji, Chieko| |
| Abstract | The behavior of multicomponent plasmas in the Penning-Malmberg traps is discussed with the parameters corresponding to experiments with antiprotons and cryogenic electrons. The relaxation times for the energy transfer antiprotons to electrons and between parallel and perpendicular components of electrons are estimated. It is shown that, depending on the values of parameters, both the former and the latter can be the bottleneck in the cooling process. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 1999-04-27 |
| Volume | volume33 |
| Issue | issue2 |
| Start Page | 61 |
| End Page | 69 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002309106 |
| Author | Murata, Atsuo| Hayami, Takehito| Moriwaka, Makoto| |
|---|---|
| Published Date | 2009-11-10 |
| Publication Title | Proceedings : Fifth International Workshop on Computational Intelligence & Applications |
| Volume | volume2009 |
| Issue | issue1 |
| Content Type | Conference Paper |
| JaLCDOI | 10.18926/19671 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_33_2_51.pdf |
| Author | Totsuji, Hiroo| Tsuruta, Kenji| Totsuji, Chieko| |
| Abstract | Density functional molecular dynamics method is applied to hydrogen plasma in the domain of liquid metallic hydrogen. Tentative results for the proton-proton pair distribution function and the electron-proton pair distribution function are obtained. It is shown that with the increase of the parameter γ(s), we have increasingly strong screening of proton charge by electrons and the decrease of electron density in the domain between protons. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 1999-04-27 |
| Volume | volume33 |
| Issue | issue2 |
| Start Page | 51 |
| End Page | 59 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002309192 |
| Author | Ghazalli Zakri| Murata, Atsuo| |
|---|---|
| Published Date | 2009-11-10 |
| Publication Title | Proceedings : Fifth International Workshop on Computational Intelligence & Applications |
| Volume | volume2009 |
| Issue | issue1 |
| Content Type | Conference Paper |
| Author | Matsuo, Tetsuko| Murata, Atsuo| |
|---|---|
| Published Date | 2009-11-10 |
| Publication Title | Proceedings : Fifth International Workshop on Computational Intelligence & Applications |
| Volume | volume2009 |
| Issue | issue1 |
| Content Type | Conference Paper |
| Author | Ibraheem Abdul| Murata, Atsuo| |
|---|---|
| Published Date | 2009-11-10 |
| Publication Title | Proceedings : Fifth International Workshop on Computational Intelligence & Applications |
| Volume | volume2009 |
| Issue | issue1 |
| Content Type | Conference Paper |
| Author | Ibraheem Abdul| Murata, Atsuo| |
|---|---|
| Published Date | 2009-11-10 |
| Publication Title | Proceedings : Fifth International Workshop on Computational Intelligence & Applications |
| Volume | volume2009 |
| Issue | issue1 |
| Content Type | Conference Paper |
| JaLCDOI | 10.18926/19660 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_33_2_25.pdf |
| Author | Song Baoyin| Inaba, Hideo| Horibe, Akihiko| |
| Abstract | A set mathematical models was developed for predicting the performance of an open-type flat-plate solar collector, and solved numerically through an implicit difference method. The effects of various parameters on the absorption of solar energy for the collector were investigated. The results showed that the solar energy absorptance of the open-type flat-plate collector was relatively high especially for the region where the weather was humid and hot, and there were an optimum length and an optimum tilt angle for the absorbing plate on which the collector could obtain the highest solar energy absorptance. It was found that the latent heat flux of water evaporation could be 5 to 15 times larger than the sensible heat flux. The effects of the magnitude of the solar incident flux, the atmospheric humidity, the atmospheric temperature, the absorbing plate tilt angle, and water film thickness on the temperature rising of the water film were clarified in numerical quantities. The increase of the solar incident flux, the atmospheric humidity or the atmospheric temperature also resulted in a rise in the energy absorptance of the collector. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 1999-04-27 |
| Volume | volume33 |
| Issue | issue2 |
| Start Page | 25 |
| End Page | 37 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002308992 |
| JaLCDOI | 10.18926/19648 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_33_2_1.pdf |
| Author | Omura, Yasuhiro| Hida, Moritaka| Sakakibara, Akira| Takemoto, Yoshito| |
| Abstract | Molecular dynamics simulation of nickel crystal under uniaxial tensile and compressive deformation was performed for single nenocrystal model and twinned nanocrystal model composed of 1550 atoms using EAM (embedded atom method) potential with the object of investigating deformation induced phase tranformation (especially twin deformation). In the case of single nanocrystal model, the evolution and development of twin deformation, (111)[11(2)], is observed under compressive loading in [001] direction, whereas either slip or twin deformation is not recognized under tensile loading. In the case of twinned nanocrystal model, twin, (111)[11(2)], decreases and disappears under tensile loading, and develops under compressive loading, It is suggested from the difference of results between single nanocrystal model and twinned nanocrystal model that it is easy for twin to induce local deformation. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 1999-04-27 |
| Volume | volume33 |
| Issue | issue2 |
| Start Page | 1 |
| End Page | 8 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002309020 |
| JaLCDOI | 10.18926/19628 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_32_1.pdf |
| Author | Guo, Changning| Uno, Yoshiyuki| Okada, Akira| Takagi, Takashi| |
| Abstract | Low electrode wear EDM is attained by the adhesion of heat resolved carbon made from kerosine type machining fluid to the electrode end surface. This phenomenon, however, occurs only under long pulse duration. Therefore, the low electrode wear EDM under finishing condition is impossible so far. In the previous paper, the authors developed a turbostratic carbon electrode whose structure is very similar to the heat resolved carbon generated in EDM process and made it clear that the low electrode wear EDM was possible by using the electrode even under finishing condition. In this study, a carbon coated electrode and a SiC coated one which can be made rapidly at low cost were developed and their EDM characteristics were investigated. Experimental analysis pointed it out that both electrodes were effective in reducing electrode wear under finishing condition. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 1998-04-20 |
| Volume | volume32 |
| Issue | issue1-2 |
| Start Page | 1 |
| End Page | 6 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002309140 |
| Author | Murata, Atsuo| Hiramatsu, Yasutaka| |
|---|---|
| Published Date | 2009-11-12 |
| Publication Title | Proceedings : Fifth International Workshop on Computational Intelligence & Applications |
| Volume | volume2009 |
| Issue | issue1 |
| Content Type | Conference Paper |
| JaLCDOI | 10.18926/19589 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_31_2_11.pdf |
| Author | Ishii Kouta| Takemoto, Yoshito| Hida, Moritaka| |
| Abstract | Fine particles of Ti-V alloy were prepared by means of arc method and were investigated on internal structure and phase transformation using HR-TEM and EDS. Martensite phase was observed in a particle containing comparatively low concentration of V, and ω phase was also found to exist in a nearly 15% V particle. The structure of the ω phase in the fine particle is remarkably expanded in comparison with the bulk sample, and the ω phase is unstable, so that it has disappeared in a few seconds during TEM observation. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 1997-03-28 |
| Volume | volume31 |
| Issue | issue2 |
| Start Page | 11 |
| End Page | 20 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002309004 |
| JaLCDOI | 10.18926/19588 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_31_2_1.pdf |
| Author | Arisawa Hideaki| Song Zhi-Yi| Takemoto, Yoshito| Hida, Moritaka| |
| Abstract | The microstructure of oxidizing magnesium at elevated temperatures has been studied using HR-TEM, SEM and EDS. Two kinds of thin magnesium specimen for TEM observation were prepared. One was oxidized after preparing TEM foil of magnesium, the other was prepared from an oxidized bulk magnesium for observing the cross-section of oxide/Mg interfacial region. In the former, several oxides(MgO) morphologies were observed depending on the temperature and time of the oxidization. The growth of needle-like oxides formed at 573K and mottled oxides formed at 773K were recognized as a remarkable phenomenon belonging to the local oxidization. These oxides were composed of poly-crystal. The thin uniform oxidization layer was also observed in all conditions. In the cross-sectional observation, the local oxide layer, nearly 300nm in thickness, on the matrix(Mg) were observed. The thin uniform oxidized layer of bulk samples was identified as a kind of modified layer (~40nm in thickness) in which the formation of HR-TEM lattice fringes were prevented by the strain due to the slight oxidization. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 1997-03-28 |
| Volume | volume31 |
| Issue | issue2 |
| Start Page | 1 |
| End Page | 10 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002309082 |
| JaLCDOI | 10.18926/17853 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_43_113.pdf |
| Author | Sakemi, Yumi| Kato, hidehiro| Nogami, Yasuyuki| Morikawa, Yoshikawa| |
| Abstract | Barreto–Naehrig (BN) curve has been introduced as an efficient pairing-friendly elliptic curve over prime field F(p) whose embedding degree is 12. The characteristic and Frobenius trace are given as polynomials of integer variable X. The authors proposed an improvement of Miller's algorithm of twisted Ate pairing with BN curve by applying X of small hamming weight in ITC–CSCC2008; however, its cost evaluation has not been explicitly shown. This paper shows the detail of the cost evaluation. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 2009-01 |
| Volume | volume43 |
| Start Page | 113 |
| End Page | 116 |
| ISSN | 1349-6115 |
| language | English |
| File Version | publisher |
| NAID | 120002308945 |
| JaLCDOI | 10.18926/17851 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_43_108.pdf |
| Author | Nekado, Kenta| Kato, Hidehiro| Nogami, Yasuyuki| Morikawa, Yoshitaka| |
| Abstract | Recently, pairing-based cryptographies such as ID-based cryptography and group signature have been studied. For fast pairing calculation, not only pairing algorithms but also arithmetic operations in extension field must be efficiently carried out. The authors show efficient arithmetic operations of extension field for Xate pairing especially with Freeman curve. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 2009-01 |
| Volume | volume43 |
| Start Page | 108 |
| End Page | 112 |
| ISSN | 1349-6115 |
| language | English |
| File Version | publisher |
| NAID | 120002308904 |
| JaLCDOI | 10.18926/17849 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_43_99.pdf |
| Author | Kato, Hidehiro| Nogami, Yasuyuki| Morikawa, Yoshitaka| |
| Abstract | A square root (SQRT) algorithm in extension field F(p(m))(m = r(0)r(1)･･･r(n−1)･2(d), r(i) : odd prime, d : positive integer) is proposed in this paper. First, a conventional SQRT algorithm, the Tonelli-Shanks algorithm, is modified to compute the inverse SQRT in F(p(2d)), where most of the computations are performed in the corresponding subfields F(p(2i)) for 0 ≤ i ≤ d-1. Then the Frobenius mappings with addition chain are adopted for the proposed SQRT algorithm, in which a lot of computations in a given extension field F(p(m)) are also reduced to those in a proper subfield by the norm computations. Those reductions of the field degree increase efficiency in the SQRT implementation. The Tonelli-Shanks algorithm and the proposed algorithm in F(p(6)) and F(p(10)) were implemented on a Core2 (2.66 GHz) using the C++ programming language. The computer simulations showed that, on average, the proposed algorithm accelerated the SQRT computation by 6 times in F(p(6)), and by 10 times in F(p(10)), compared to the Tonelli-Shanks algorithm. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 2009-01 |
| Volume | volume43 |
| Start Page | 99 |
| End Page | 107 |
| ISSN | 1349-6115 |
| language | English |
| File Version | publisher |
| NAID | 120002308980 |
| JaLCDOI | 10.18926/17831 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_43_22.pdf |
| Author | Totsuji, Hiroo| Chai Hong| Totsuji, Chieko| Tsuruta, Kenji| |
| Abstract | For the transfer of quantum information and the creation of entangled states, the application of tuned spin chains, systems of spins with the nearest-neighbor coupling tuned so as to give high efficiency, has been proposed and some examples of high performance have been given by several authors. In this article, the effect of deviations from tuned values and the effect of resultant asymmetry are investigated through numerical simulations and theoretical analyses. It is shown that there exists a system where the transfer efficiency is comparable with exactly tuned ones and, at the same time, robust to noises in the coupling constants. It is also shown that the effect of asymmetry on the efficiency of entanglement creation is of the second order when the asymmetry is small. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 2009-01 |
| Volume | volume43 |
| Start Page | 22 |
| End Page | 26 |
| ISSN | 1349-6115 |
| language | English |
| File Version | publisher |
| NAID | 120002308966 |
| JaLCDOI | 10.18926/17829 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_43_16.pdf |
| Author | Kurose Tomoyuki| Tsuruta, Kenji| Totsuji, Chieko| Totsuji, Hiroo| |
| Abstract | The finite-difference time-domain (FDTD) method has been applied to the calculation of the phonon band structure of two-dimensional (2D) phononic crystals, consisting of metal cylinders placed periodically in liquid. By comparing several combinations of materials for metal cylinder and liquid, we analyze the dependence of the band structures on sound speed and density of liquid media. Moreover, the negative refraction of the acoustic waves is observed at the interfaces between phononic crystal slab and the liquid. We find that an acoustic“lens effect”with the slab appears due to the negative refractions. The relationship between the focal intensity in the lens effect and the band structure is discussed. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 2009-01 |
| Volume | volume43 |
| Start Page | 16 |
| End Page | 21 |
| ISSN | 1349-6115 |
| language | English |
| File Version | publisher |
| NAID | 120002308928 |
| JaLCDOI | 10.18926/17826 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_43_8.pdf |
| Author | Umeda Ryosuke| Totsuji, Chieko| Tsuruta, Kenji| Totsuji, Hiroo| |
| Abstract | Metamaterial which has negative permittivity and permeability is investigated via computer simulations. Effects of the nanostructure on dielectric and magnetic properties of the material are taken into account by introducing the Drude-Lorentz model in the materials dispersion. We include multi-band process in the dielectric response in order to reproduce accurately experimental values of bulk Au thin film. Size effect on the dispersion is examined by comparing the model with that of a noble metal particle. Based on the dispersion model constructed, we analyze the electromagnetic response of nanostructured metamaterials to evanescent waves at microwave and optical frequencies via finite-difference time-domain simulatioins on parallel computer. A re- focusing and an amplification of the evanescent waves propagating through a metamaterial, consisting of metal slab/vacuum stacking, is demonstrated for the frequencies of 30GHz and 744THz. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 2009-01 |
| Volume | volume43 |
| Start Page | 8 |
| End Page | 15 |
| ISSN | 1349-6115 |
| language | English |
| File Version | publisher |
| NAID | 120002308833 |
| JaLCDOI | 10.18926/15837 |
|---|---|
| FullText URL | Mem_Sch_Eng_OU_21_2_1.pdf |
| Author | Takemoto Yoshito| Hida Moritaka| |
| Abstract | We investigated the effects of resolved interstitial oxygen or nitrogen atoms and of quenched-in strain on the hardening of the single crystals grown from molten Ti-14 and 20wt pct Mo alloys. The aging treatment at 623K in atmosphere much more increased in the hardness of specimen surface than that in argon atmosphere. The quenched-in compressive stress enhanced age hardening due to omega formation. We surveyed in detail the hardness changes toward the center of plate-shaped single crystal. |
| Publication Title | Memoirs of the School of Engineering, Okayama University |
| Published Date | 1987-03-05 |
| Volume | volume21 |
| Issue | issue2 |
| Start Page | 1 |
| End Page | 7 |
| ISSN | 0475-0071 |
| language | Japanese |
| File Version | publisher |
| NAID | 120002307640 |
