| JaLCDOI | 10.18926/19637 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_32_43.pdf |
| Author | Totsuji, Chieko| Matsubara Takeo| |
| Abstract | Large isotope effects have been observed in various kinds of hydrogen bonded ferro / antiferroelectrics. In clariflying their origin, themodynamic properties of the hydrogen bond are of essential importance. Two numerical methods are applied to analyze the model for isolated hydrogen bond at finite temperatures and the results of excited energy levels of proton or deuteron are examined. It is found that the second excited state is not far enough from the first excited state to be neglected discussing themodynamic properties of hydrogen especially in their ordered states. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 1998-04-20 |
| Volume | volume32 |
| Issue | issue1-2 |
| Start Page | 43 |
| End Page | 54 |
| ISSN | 0475-0071 |
| language | 英語 |
| File Version | publisher |
| NAID | 120002309098 |
| JaLCDOI | 10.18926/15508 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_25_2_25.pdf |
| Author | Nsunge Felix Chintu| Tomiｔa, Eiji| Hamamoto, Yoshisuke| |
| Abstract | A suddenly started cold methane gas jet issuing from a 1 mm diameter orifice into still air at Mach one has been predicted using the two-equation, high Reynolds number version of k-ε turbulence model and SIMPLE algorithm which employs so called primitive variables and a hybrid scheme for treating combined diffusion and convection. Global trends of predicted radial distributions of velocity, temperature, methane concentration in the steady rear part of the transient jet and axial jet tip penetration compare reasonably well with universal profiles representing measurement for the steady jet particularly in the fully developed turbulent core and semi-empirical relation for the transient jet respectively. The prediction scheme has shown reasonably good accuracy especially in prediction of main flow parameters of a transient, high speed compressible gas jet issuing into a dissimilar surrounding gas(binary gas mixture jet). |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 1991-03-28 |
| Volume | volume25 |
| Issue | issue2 |
| Start Page | 25 |
| End Page | 38 |
| ISSN | 0475-0071 |
| language | 英語 |
| File Version | publisher |
| NAID | 120002307676 |
| JaLCDOI | 10.18926/19954 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_44_7.pdf |
| Author | Maetani Noriaki| Kurose Tomoyuki| Tsuruta, Kenji| |
| Abstract | The lens effect of acoustic waves in a two-dimensional (2D) phononic crystal is studied by numerical simulation based on the finite-difference time-domain (FDTD) method. We calculate the phonon band structure of 2D phononic crystals, consisting of metal cylinders placed periodically in water. Lens effect is observed by the negative refraction of acoustic waves, which results in refocusing of the waves at the point outside the crystal. To increase the focal intensity, we introduce a 2D phononic crystal shield with a different composition of material, which returns the incident waves back to the lens via the perfect reflection. Also, the dependence on filling fraction of metal in the crystal is studied. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 2010-01 |
| Volume | volume44 |
| Start Page | 7 |
| End Page | 12 |
| ISSN | 1349-6115 |
| language | 英語 |
| File Version | publisher |
| NAID | 120002309019 |
| JaLCDOI | 10.18926/15487 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_24_1_135.pdf |
| Author | Taniguhi, Takeo| Suetsugu, Tsuyoshi| Iwasaki Masaki| |
| Abstract | This paper describes the numerical simulation method of the multi-crack propagation behaviour which appear in a part of civil engineering structures with complex geometrical configuration like steel bridges. Proposed method can treat the interaction of several cracks which locate in a short distance each other, and the process of their growth can be grasped. The method is based on the finite element method, and the linear fracture mechanics is assumed. Proposed method includes following tools for the simulation of the crack propagation behaviour: Automatic Mesh Generators for 3-D, 2-D structural analysis, and 2-D crack propagation analysis, Multi-level Structural Analysis Technique, Estimation Method of the crack growth and the angle of cracks and the modelling method of traffic loadings. The validity of the method is investigated by comparing the result to the experimental one. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 1989-11-29 |
| Volume | volume24 |
| Issue | issue1 |
| Start Page | 135 |
| End Page | 152 |
| ISSN | 0475-0071 |
| language | 英語 |
| File Version | publisher |
| NAID | 120002307854 |
| JaLCDOI | 10.18926/15460 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_28_2_45.pdf |
| Author | Totsuji, Hiroo| Hashimoto, Seiji| Nara, Shigetoshi| |
| Abstract | Difficulties in simulating systems composed of classical and quantum particles lie in the treatment of the many-body interactions between quantum particles and the geometrical variety of configurations of classical particles. In order to overcome these difficulties, we have developed some numerical methods and applied them to simple cases. As for stationary states, the finite element method provides us with sufficient geometrical freedom. Combined with the Kohn-Sham equation based on the density functional theory, this method virtually satisfies our requirement. In order to investigate time-dependent phenomena, we apply the time-dependent Kohn-Sham equation. Adopting the finite difference method, we are able to follow the development of quantum many-body system. As an example, we estimate the effects of the potential height, the electric field, and many-body interactions in some transition processes in quantum wells coupled by a tunneling barrier. This example is important in itself in relation to semiconductor superlattices and also serves as a benchmark for quantum simulations, variety of geometry corresponding to that of classical particles. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 1994-03-15 |
| Volume | volume28 |
| Issue | issue2 |
| Start Page | 45 |
| End Page | 52 |
| ISSN | 0475-0071 |
| language | 英語 |
| File Version | publisher |
| NAID | 120002307158 |
| JaLCDOI | 10.18926/15447 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_28_1_129.pdf |
| Author | Taniguchi, Takeo| Hirose, Sohichi| Ouchterlony Finn| Nakagawa Kohji| Miyaji Akihiko| Fukuoka Yasufumi| |
| Abstract | The testing method of rock toughness is proposed by the international society of rock mechanics (ISRM), but the results may be influenced by the test pieces, and the details of the crack propagation and the stress intensity factors are not clarified through the testing. Also the experimental test requires tedious works for the preparation of test specimen and economical responsibility. The present study aims to simulate numerically the rock toughness testing which is proposed by ISRM. For this purpose, the authors propose a numerical method which can simulate the experimental testing, and they show the propriety of the proposed method by comparing the results with the experimental and other numerical methods. At the same time, they clarify the details of crack propagation behaviors in rocks, and show the change of the stress intensity factors. The proposed method is based on the displacement-type finite element method, and several techniques are introduced to obtain accurate solution of the mechanical behavior near the crack-tip area. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 1993-11-30 |
| Volume | volume28 |
| Issue | issue1 |
| Start Page | 129 |
| End Page | 138 |
| ISSN | 0475-0071 |
| language | 英語 |
| File Version | publisher |
| NAID | 120002307126 |
| JaLCDOI | 10.18926/14059 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_42_48.pdf |
| Author | Totsuji, Chieko| Miyake Takashi| Nakanishi Kenta| Tsuruta, Kenji| Totsuji, Hiroo| |
| Abstract | Based on the mapping introduced by the classical-map hypernetted-chain (CHNC) method, classical numerical simulations, Monte Carlo and molecular dynamics, have been applied to the twodimensional electron fluid and the results are compared with those of quantum Monte Carlo simulations hitherto reported. It is shown that polarization properties of the ground state obtained by the diffusion Monte Carlo method are reproduced within the accuracy of quantum simulations by both of two mapping functions for the quantum temperature which have been proposed within the CHNC method. These results may serve as the basis of numerical simulations based on the CHNC method which are applicable to finite non-periodic systems like quantum dots and systems at finite temperatures. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 2008-01 |
| Volume | volume42 |
| Issue | issue1 |
| Start Page | 48 |
| End Page | 52 |
| ISSN | 0475-0071 |
| language | 英語 |
| File Version | publisher |
| NAID | 120002308425 |
| JaLCDOI | 10.18926/47022 |
|---|---|
| FullText URL | mfe_36_2_007_013.pdf |
| Author | Abe, Takeji| Nagao, Makoto| Ohta, Tomoyuki| Nagayama, Noriyuki| |
| Abstract | It is important to study the microscopic deformation behavior of inhomogeneous material, for most engineering materials are inhomogeneous. The aim of the present study is to clarify by numerical analysis some features of microscopic plastic strain distributions, the mean flow stress and the material factors affecting on it. The rigid-plastic solution is important not only for plastic deformation problems with large strain, but also for creep deformation problems through the plastic analogy in the creep analysis. The effects of material parameter and loading conditions on the deformation behavior of the material are examined and discussed based on the result of calculation. The effects of the aspect ratio of the inhomogeneous regions on the deformation mode are studied. The patterns of the strain concentration and the averaged flow stress of the inhomogeneous material are also discussed. The results of rigid-plastic material are compared with those of the elastic material. |
| Keywords | Plasticity Deformation Inhomogeneous Material Strain Concentration Coefficient Rigid-Plastic FEM |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 2002-03 |
| Volume | volume36 |
| Issue | issue2 |
| Start Page | 7 |
| End Page | 13 |
| ISSN | 0475-0071 |
| language | 英語 |
| File Version | publisher |
| NAID | 120003497044 |
| JaLCDOI | 10.18926/15409 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_29_2_5.pdf |
| Author | Inaba, Hideo| Tu Ping| Ozaki, Koichi| |
| Abstract | Transient characteristics of the rectangular latent heat storage vessel packed with shape-stabilized phase change (solid-liquid) material (PCM) are investigated numerically by solving the governing equations of both the PCM and the heat transfer medium(water) simultaneously as a conjugate problem with the finite difference technique. It's found that the heat storage characteristics are greatly affected by the flow direction of the heat transfer medium since the natural and forced convection coexists in the heat storage vessel. That is, it is classified that the effectively thermal efficiency of the latent heat storage system is obtained by the downflow along vertical PCM for heat storage process and the upflow for heat release process. The effect of the inlet velocity of heat transfer medium(water) on transient heat characteristics of the latent heat storage system is also revealed in the present study. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 1995-03-27 |
| Volume | volume29 |
| Issue | issue2 |
| Start Page | 5 |
| End Page | 12 |
| ISSN | 0475-0071 |
| language | 英語 |
| File Version | publisher |
| NAID | 120002307377 |
| JaLCDOI | 10.18926/19674 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_33_2_71.pdf |
| Author | Tsuruta, Kenji| Totsuji, Hiroo| Totsuji, Chieko| |
| Abstract | A parallel tight-binding molecular dynamics with an order-N [O(N))] algorithm is implemented to perform large-scale simulation of nanostructured materials. The algorithm is based on the Fermi-operator expansion of an electronic energy and force, and we present its basic formalisms. Accuracy necessary for molecular-dynamics simulations can be obtained by a proper truncation in the expansion. Parallel efficiency on a parallel PC cluster shows nearly ideal scaling behavior with respect to the number of processors. Applicability of the method to a silicon-carbide system is examined. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 1999-04-27 |
| Volume | volume33 |
| Issue | issue2 |
| Start Page | 71 |
| End Page | 77 |
| ISSN | 0475-0071 |
| language | 英語 |
| File Version | publisher |
| NAID | 120002309027 |
| JaLCDOI | 10.18926/46976 |
|---|---|
| FullText URL | mfe_37_2_005_012.pdf |
| Author | Abe, Takeji| Sato, Takashi| |
| Abstract | Cork is a material that has many characteristics, for instance, light weight, elasticity, insulation against heat, impermeability for liquid, and so forth. There are two types of cork, the natural and the agglomerated corks. In the present paper, compression tests of the natural and the agglomerated cork specimens were carried out. The compression test were done in various directions. Compressive stress was measured by a original compression apparatus, and stress-strain curves were obtained in various directions of the cork specimens. In the natural cork, there are differences between the radial and the non-radial direction. The recovery of dimensions after compression was also studied in respective directions. The structure of the deformed surface was observed by a scanning electron microscope. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 2003-03 |
| Volume | volume37 |
| Issue | issue2 |
| Start Page | 5 |
| End Page | 12 |
| ISSN | 0475-0071 |
| language | 英語 |
| File Version | publisher |
| NAID | 80015999990 |
| JaLCDOI | 10.18926/46995 |
|---|---|
| FullText URL | mfe_36_1_001_006.pdf |
| Author | Kondou, Ryouji| Abe, Takeji| Tada, Naoya| Shimizu, Ichiro| |
| Abstract | Change in crystal orientation and strain of individual grains during tensile plastic deformation are studied to clarify on the microscopic deformation behavior of polycrystalline copper. The orientation of grain is measured by electron backscatter diffraction (EBSD) technique in the scanning electron microscope. The principal strain of grain is also measured by obtaining the approximated ellipse of strain distribution. The deformation of grains dependent on their initial orientation and the rotation of the principal strain during uniaxial tension are clarified. |
| Keywords | Polycrystalline Copper Plastic Deformation SEM EBSD Method Grain Orientation Crystal Orientation Map |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 2001-12 |
| Volume | volume36 |
| Issue | issue1 |
| Start Page | 1 |
| End Page | 6 |
| ISSN | 0475-0071 |
| language | 英語 |
| File Version | publisher |
| NAID | 120003497021 |
| JaLCDOI | 10.18926/15478 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_23_2_45.pdf |
| Author | Taniguchi, Takeo| Fujiwara, Kohji| |
| Abstract | This paper includes a solver for a large sparse set of linear algebraic equations which are obtained by the application of the finite element method to static structural problems. Proposed method is a modification of Robust Incomplete Choleski-Conjugate Gradient Method, which belongs to Preconditioned Conjugate Gradient Method suitable for supercomputers. Through a number of numerical experiments the authors show that Robust Incomplete Choleski-Conjugate Gradient Method sometimes fails in to obtain the solutions, secondly they clarify the reason of the failures from the theoretical viewpoint, and finally they propose a modification of the robust method by the introduction of the theoretical result. Proposed method is as effective as the original, and it can overcome the demerit of Robust Method which is clarified through numerical experiments. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 1989-03-30 |
| Volume | volume23 |
| Issue | issue2 |
| Start Page | 45 |
| End Page | 55 |
| ISSN | 0475-0071 |
| language | 日本語 |
| File Version | publisher |
| NAID | 120002307820 |
| JaLCDOI | 10.18926/15422 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_29_2_57.pdf |
| Author | Totsuji, Hiroo| |
| Abstract | As plasmas with extremely reduced dimensionality, properties of one-dimensional classical plasmas are analyzed in the domain of strong coupling and static and dynamic structure factors and the plasmon dispersion relation are obtained. These plasmas may be realized in Penning traps with sufficiently strong confinement and also in semiconductor quantum wires under appropriate conditions. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 1995-03-27 |
| Volume | volume29 |
| Issue | issue2 |
| Start Page | 57 |
| End Page | 65 |
| ISSN | 0475-0071 |
| language | 英語 |
| File Version | publisher |
| NAID | 120002307838 |
| JaLCDOI | 10.18926/15449 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_22_15.pdf |
| Author | Furutani, Yoichiro| Totsuji, Hiroo| Komaki Kunitaka| Tanabe Masahiro| |
| Abstract | An effective potential of an isolated partially ionized high-Z ion, calculated within the framework of the statistical models of atoms, is injected into the one-electron Schrödinger equation, in view of evaluating the electron density and comparing it with the results of statistical models. Starting from this initial value, a self-consistent electron density is obtained on the basis of the density functional theory, where quantum natures of electrons are fully taken into account. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 1988-03-31 |
| Volume | volume22 |
| Start Page | 15 |
| End Page | 34 |
| ISSN | 0475-0071 |
| language | 英語 |
| File Version | publisher |
| NAID | 120002307361 |
| JaLCDOI | 10.18926/44498 |
|---|---|
| FullText URL | mfe_045_036_045.pdf |
| Author | Kanatani, Kenichi| Niitsuma, Hirotaka| |
| Abstract | We present a new method for optimally computing the 3-D rotation from two sets of 3-D data. Unlike 2-D data, the noise in 3-D data is inherently inhomogeneous and anisotropic, reflecting the characteristics of the 3-D sensing used. To cope with this, Ohta and Kanatani introduced a technique called “renormalization”. Following them, we represent a 3-D rotation in terms of a quaternion and compute an exact maximum likelihood solution using the FNS of Chojnacki et al. As an example, we consider 3-D data obtained by stereo vision and optimally compute the 3-D rotation by analyzing the noise characteristics of stereo reconstruction. We show that the widely used method is not suitable for 3-D data. We confirm that the renormalization of Ohta and Kanatani indeed computes almost an optimal solution and that, although the difference is small, the proposed method can compute an even better solution. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 2011-01 |
| Volume | volume45 |
| Start Page | 36 |
| End Page | 45 |
| ISSN | 1349-6115 |
| language | 英語 |
| Copyright Holders | Copyright © by the authors |
| File Version | publisher |
| NAID | 80021759250 |
| JaLCDOI | 10.18926/48127 |
|---|---|
| FullText URL | mfe_046_021_033.pdf |
| Author | Kanatani, Kenichi| Niitsuma, Hirotaka| |
| Abstract | Because 3-D data are acquired using 3-D sensing such as stereo vision and laser range finders, they have inhomogeneous and anisotropic noise. This paper studies optimal computation of the similarity (rotation, translation, and scale change) of such 3-D data. We first point out that the Gauss-Newton and the Gauss-Helmert methods, regarded as different techniques, have similar structures. We then combine them to define what we call the modified Gauss-Helmert method and do stereo vision simulation to show that it is superior to either of the two in convergence performance. Finally, we show an application to real GPS geodetic data and point out that the widely used homogeneous and isotropic noise model is insufficient and that GPS geodetic data are prone to numerical problems. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 2012-01 |
| Volume | volume46 |
| Start Page | 21 |
| End Page | 33 |
| ISSN | 1349-6115 |
| language | 英語 |
| Copyright Holders | Copyright © by the authors |
| File Version | publisher |
| NAID | 80022451622 |
| JaLCDOI | 10.18926/48125 |
|---|---|
| FullText URL | mfe_046_001_009.pdf |
| Author | Kanatani, Kenichi| Niitsuma, Hirotaka| |
| Abstract | We optimally estimate the similarity (rotation, translation, and scale change) between two sets of 3-D data in the presence of inhomogeneous and anisotropic noise. Adopting the Lie algebra representation of the 3-D rotational change, we derive the Levenberg-Marquardt procedure for simultaneously optimizing the rotation, the translation, and the scale change. We test the performance of our method using simulated stereo data and real GPS geodetic sensing data. We conclude that the conventional method assuming homogeneous and isotropic noise is insufficient and that our simultaneous optimization scheme can produce an accurate solution. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 2012-01 |
| Volume | volume46 |
| Start Page | 1 |
| End Page | 9 |
| ISSN | 1349-6115 |
| language | 英語 |
| Copyright Holders | Copyright © by the authors |
| File Version | publisher |
| NAID | 80022451620 |
| JaLCDOI | 10.18926/44495 |
|---|---|
| FullText URL | mfe_045_001_014.pdf |
| Author | Akiyoshi, Tatsuro| Imai, Jun| Konishi, Masami| |
| Abstract | This paper presents a method of the controller design for the handling machine by using dsPIC(Digital Signal Processor + Peripheral Interface Controller). Recently, many manufacturing robots are operated in manufacturing facilities, with the aim of labor, cost saving, and improvement of the productivity. Such robots need to have positioning performance of high precision and simultaneously to save cost. In this paper, a digital optimal servo controller is designed, and it is implemented into our barebones controller which involves dsPIC. We have designed and manufactured the controller which is added suitable peripherals to improve the consistency between the mechanical machine operating in continuous time and controller in discrete time. The significance of this research is that digital implementation of the embedded system which has performance-limitation has ensured a comparable result, against the one with PC which has broad utility. When it is used as a controller, it is possible to restrain product prices greatly equivalent PC precision. We demonstrate potential that good control can be achieved even with low cost. Our research has lead to the viability of lower cost and higher performance system for the production process at factories. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 2011-01 |
| Volume | volume45 |
| Start Page | 1 |
| End Page | 14 |
| ISSN | 1349-6115 |
| language | 英語 |
| Copyright Holders | Copyright © by the authors |
| File Version | publisher |
| NAID | 120002905951 |
| JaLCDOI | 10.18926/15494 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_25_1_71.pdf |
| Author | Myojin Sho| Yamada Masahito| Fujii Naoto| |
| Abstract | A transportation planning way of approach is applied to optimal pricing and planning of urban expressway network. Two kinds of network are investigated ; four radials with one ring system and four radials with two rings system. The model is composed of three submodels ; road systell, trip generation-attraction and traffic diversion. Some iaplicative aspects are shown of the optimal solutions that maximize the aggregate number of the trips diverted to expressway under constraints ; equilibrium of revenue and expenditure and traffic capacity constraint. (1) traffic flow has the peaks at junctions on radial expressway that are adjusted to be equal to the traffic capacity. (2) two rings system realizes the larger aggregate number of diverted trips by lower toll rate than one ring system does. (3) well-located second ring has a remarkable effect on improvement in accessibility to expressway and (4) some parameters in the model have curious effects on the optimal system. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 1990-12-14 |
| Volume | volume25 |
| Issue | issue1 |
| Start Page | 71 |
| End Page | 87 |
| ISSN | 0475-0071 |
| language | 英語 |
| File Version | publisher |
| NAID | 120002307618 |
