JaLCDOI 10.18926/15486
FullText URL Mem_Fac_Eng_OU_25_1_23.pdf
Author Miura, Yoshinari| Takada, Jun| Osaka, Akiyoshi| Kawamura, Toshio|
Abstract Zinc oxide films were prepared on silica glass substrates by the use of an r.f. activated reactive evaporation (ARE) method, and were examined by X-ray diffraction (XRD) and scanning electron micrograph (SEM). XRD measurements indicate that the films were c-axis oriented and that an r.f. plasma of Zn and O was necessary for the ZnO film deposition. Substrate temperature, oxygen gas pressure, evaporation rate, r.f. power and inlet position of oxygen gas effect the c-axis orientation, the growth rate and the microstructure of the films. Optimum conditions for a dense film with a fine texture of the surface and having good crystallinity were as follows: the substrate temperature;400℃, the evaporation rate;5.0(A)/s, the oxygen pressure;2.0x10(-4) Torr, the r.f. power;150 to 200W, and the oxygen gas inlet near the substrate. For the film prepared under the optimum conditions, the standard deviation σ of the rocking curve for the (002) diffraction was 1.9deg, smaller than that of the film prepared by using an r.f. sputtering method.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1990-12-14
Volume volume25
Issue issue1
Start Page 23
End Page 35
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307600
JaLCDOI 10.18926/48126
FullText URL mfe_046_010_020.pdf
Author Kanatani, Kenichi|
Abstract We present a new technique for calibrating ultra-wide fisheye lens cameras by imposing the constraint that collinear points be rectified to be collinear, parallel lines to be parallel, and orthogonal lines to be orthogonal. Exploiting the fact that line fitting reduces to an eigenvalue problem, we do a rigorous perturbation analysis to obtain a Levenberg-Marquardt procedure for the optimization. Doing experiments, we point out that spurious solutions exist if collinearity and parallelism alone are imposed. Our technique has many desirable properties. For example, no metric information is required about the reference pattern or the camera position, and separate stripe patterns can be displayed on a video screen to generate a virtual grid, eliminating the grid point extraction processing.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 2012-01
Volume volume46
Start Page 10
End Page 20
ISSN 1349-6115
language 英語
Copyright Holders Copyright © by the authors
File Version publisher
NAID 80022451621
JaLCDOI 10.18926/15398
FullText URL Mem_Fac_Eng_OU_27_1_93.pdf
Author Nishigaki, Makoto| Sudinda Teddy| Hishiya Tomoyuki| Kohno, Ichiro|
Abstract In this paper the author will be describe phenomena of advection dispersion in subsurface flow by using Eulerian Lagrangian Finite Element Method. Where Finite Element Method with Galerkin formulation and weigthed residual method is used to solve seepage and advection dispersion equation. The problem of one dimensional and two dimensional rectangular wave are analyzed in this paper. And the result of numerical analyses will be compared with analytical solutions. The numerical results showed the very good agreement with the analytical solutions.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1992-11-25
Volume volume27
Issue issue1
Start Page 93
End Page 105
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307768
JaLCDOI 10.18926/15440
FullText URL Mem_Fac_Eng_OU_28_1_71.pdf
Author Nishigaki, Makoto| Sudinda Teddy| Hishiya Tomoyuki| Kohno, Iichiro|
Abstract In this paper, method of Eulerian Lagrangian numerical analysis is used to described Advection-Dispersion phenomena. The influence of concentration to the density of fluid is considered. A laboratory model of a two dimensional confined aquifer containing an isotropic, homogeneous porous medium (Hosokawa et.al 1989) was used to validate the applicability of Advection-Dispersion of numerical analysis with steady and unsteady state condition [1].
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1993-11-30
Volume volume28
Issue issue1
Start Page 71
End Page 85
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307975
JaLCDOI 10.18926/15442
FullText URL Mem_Fac_Eng_OU_28_1_87.pdf
Author Motojima Isao| Kono, Iichiro| Nishigaki, Makoto|
Abstract In recent years, construction or planning of large-scale underground structures, such as underground power plants, underground oil storage plants and nuclear power plants have been coming into consideration in Japan. To construct such as large-scale underground structures, one of the most important problems is to make clear beforehand the behavior of groundwater around these structures and the other is to carry out proper countermeasure of groundwater, so that these structures can be constructed safely and maintained stability over a long time period. This report describes the results of theoretical studies on the drain systems and at the same time, discusses the drain systems around the underground cavern for the practical underground power stations.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1993-11-30
Volume volume28
Issue issue1
Start Page 87
End Page 128
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307220
JaLCDOI 10.18926/15463
FullText URL Mem_Fac_Eng_OU_28_2_59.pdf
Author Nishigaki, Makoto| Sun Yao| Kohno, Iichiro|
Abstract In this paper, first, an elasto-plastic consitituve equation for unsaturated soil was developed by considering of the basically behavior of unsaturated soil. Second, the results of a number of triaxial test and a set of rigid foundation model tests were simulated by using this constitutive equation, the agreement between observed and computed results was satisfactory and confirms the possibilities of this constitutive equation.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1994-03-15
Volume volume28
Issue issue2
Start Page 59
End Page 75
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307850
JaLCDOI 10.18926/15492
FullText URL Mem_Fac_Eng_OU_25_1_59.pdf
Author Kohno, Iichiro| Nishigaki, Makoto| Okada Junji|
Abstract In this paper, we propose a method to determine the coefficients of permeability of the unconfined aquifer consisted of two different permeability layers. With mixing the conventional pumping test and falling head permeability test, the coefficients of permeabilitiy k(1) and k(2) were obtained. The validity of the proposed method is investigated by using the numerical simulation. As the results, it becomes apparent that the proposed method is applicable to real hydarulic problems.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1990-12-14
Volume volume25
Issue issue1
Start Page 59
End Page 69
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307472
JaLCDOI 10.18926/15393
FullText URL Mem_Fac_Eng_OU_30_2_15.pdf
Author Oka, Hisao| Fujiwara, Shiro|
Abstract An estimation of muscle fatigue is very important study and many laboratory researchers had done actively in this field. The excellent measurement and analysis methods, however, have not established yet. The aim of this study was to investigate the muscle fatigue of low back, caused by sitting on the vehicle seat for a long time. The muscle viscoelasticity and the EMG (Electromyogram) were measured. The authors proposed the objective muscle fatigue index that was obtained from the result of PCA (Principal Component Analysis) by using the measured varlables. The objective muscle fatigue index suggests an adequate correlation with the subjective fatigue on the vehicle seat.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1996-03-29
Volume volume30
Issue issue2
Start Page 15
End Page 20
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307965
JaLCDOI 10.18926/15400
FullText URL Mem_Fac_Eng_OU_27_2_11.pdf
Author Oka, Hisao| Yamamoto, Tatsuma| Saratani Keiji| Tanaka Masahiro| Kawazoe Takayoshi|
Abstract The use of dental implants has increased together with increases in the human life span and it has become an imperative subject for dentists to familiarize themselves with this treatment modality. Unfortunately, there has been no practical and quantitative method for in vivo evaluation of the stability of dental implants. In the tooth mobility examination, the tactile sense of natural teeth is different from that of dental implants. The authors have developed an automatic diagnosis system of tooth mobility for clinical use. The biomechanical mobility of peri-implantium is measured with a pseudo-random vibration, from which the viscoelasticity c1, c2, k of peri-implantium is obtained. The diagnosis system has been applied to the quantitative evaluation of the stability of implants : endodontics endosseous implants (titanium pin), endosseous implants (Bioceram). It has also been applied to the evaluation of the long-term prognoses of dental implantation (Bioceram) and the examination of Intramobile implant (IMZ), and the satisfactory results have been obtained.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1993-03-25
Volume volume27
Issue issue2
Start Page 11
End Page 17
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002308018
JaLCDOI 10.18926/15415
FullText URL Mem_Fac_Eng_OU_29_2_29.pdf
Author Oka, Hisao| Fukuda, Takashi|
Abstract In the stiffness evaluation from the skin surface, the body structure under the skin, like a bone and muscle, influences on the measurement results. The authors developed the measurement system of biomechanical impedance with applying a vibration of acoustic frequency onto the body surface. We measured the viscoelasticity of the silicone-gel model, which involves metal blocks, from the gel surface by using this system. The internal structure of model is estimated from the relation between the viscoelasticity and the distance from the gel surface to the internal block. Applying this method, the shape of ribs of the right chest are estimated. The shapes and viscoelasticity of silicone-gel tumor model, which has two different tumors, are also estimated.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1995-03-27
Volume volume29
Issue issue2
Start Page 29
End Page 37
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307199
JaLCDOI 10.18926/15416
FullText URL Mem_Fac_Eng_OU_26_1_43.pdf
Author Bouzidi, Moncef| Koga, Ryuji| Wada, Osami| Kagawa, Naoki| Hai Xu| Kosaka, Megumi| Sano HIroya|
Abstract A numerical technique called as "adjoint spectrum" has been proposed by the authors in a previous work. Two applications of it are presented here. It is demonstrated that by generalizing the aspect of adjoint spectrum it becomes possible to measure densities of mixed gases simultaneously. An experimental proof of this has been carried on and simultaneous measurement of densities of both methane and dinitrogen oxide was realized. On the other hand, it is also reported that frequency shifting of spectra, which is a cause of error in spectrometric measurements, can be corrected by exploiting the adjoint spectrum technique in connection with the Taylor expansion. Numerical examples showing the success of this method are reported as well.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1991-11-30
Volume volume26
Issue issue1
Start Page 43
End Page 49
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307796
JaLCDOI 10.18926/15446
FullText URL Mem_Fac_Eng_OU_22_1.pdf
Author Oka, Hisao| Yamamoto, Tatsuma|
Abstract Biomechanical impedance is relatively small compared to industrial mechanical impedance. Thus it is difficult to measure it precisely. A biomechanical impedance measuring system was developed for portable use by means of random excitation. This system doesn't require a fixed body and vibrator supporting apparatus. In order to obtain an impedance spectrum, the FFT processing is performed using a personal computer. The spectra of the biomechanical impedance which is measured on body surfaces depend on body positions and can be roughly classified into three spectra patterns : soft, stiff and intermediate. During the measurement, the measuring conditions (preload, diameter of the vibrating tip etc.) influence the results. However, it became clear that the linearity of the biomechanical impedance was satisfied in the limited measuring conditions. Accordingly it is possible to standardize the impedance and to compare it with the results under different measuring conditions.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1988-03-31
Volume volume22
Start Page 1
End Page 14
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307480
JaLCDOI 10.18926/15465
FullText URL Mem_Fac_Eng_OU_23_1_49.pdf
Author Oka, Hisao| Yamamoto, Tatsuma| Isayama Yoshiharu|
Abstract In the field of dental study it is most fundamental and necessary to estimate the condition of periodontium. In order to examine a mechanical characteristics of periodontium, the theoretical displacement response to periodontal mechanical model (three elements model) are strictly solved in case of some pulse excitations. Impact excitations (rectangular, triangular and half-cycle sine pulse) are given in physical and mathematical definitions and complete solutions to the impact excitations are provided. The triangular pulse excitation which is obtained by means of a fracture of pencil-lead is most suitable. The mechanical parameters of periodontium are given using this input excitation. This is experimentally confirmed by artificial tooth model. The obtained mechanical characteristic of the periodontal tissues can be applied to clinical diagnosis.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1988-11-22
Volume volume23
Issue issue1
Start Page 49
End Page 60
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307622
JaLCDOI 10.18926/15476
FullText URL Mem_Fac_Eng_OU_24_1_63.pdf
Author Yamamoto, Yoshitake| Isshiki Hiromi| Oka, Hisao| Yamamoto, Tatsuma|
Abstract There is no doubt that many people feel the peace of mind or the pleasures of senses in appreciating music. But the estimation of the effect is very difficult and the objective estimation can be hardly done. This study proposed the objective estimating method of human emotion utilizing galvanic skin reflex (GSR) which reflects a human psychological activity. In this method, not by individual response, but by the series of response and pattern of appearance of GSR, the emotional response under appreciating music was investigated. In the case of appreciation of the same classic music to several subjects, the individual GSR responses are random and remarkable characteristic could not be find on the results. However, on the patterns of appearance of GSR, the patterns obtaining from the same generation are much similar each other and the patterns obtaining from different generation are less similar. It was cleared that the same music gave different effect on different generations.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1989-11-29
Volume volume24
Issue issue1
Start Page 63
End Page 72
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307670
JaLCDOI 10.18926/15479
FullText URL Mem_Fac_Eng_OU_24_1_73.pdf
Author Oka, Hisao| Isayama Yoshiharu| Yamamoto, Yoshitake| Yamamoto, Tatsuma|
Abstract There is a small vibration which goes undetected by the naked eyes. It is called a microvibration (MV) or a minor tremor (MT). The MV on the body surface is expected to apply to a clinical examination of the autonomic nervous system. It is not cleared why and how the MV occurs, but there are many papers about its occurrence and clinical application. In this study, MV measuring system, its estimation and basic characteristics are examined. The difference between head MV and thenar MV, individual MV and diurnal and seasonal change are discussed. The power spectrum of MV is obtained using an autoregressive model.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1989-11-29
Volume volume24
Issue issue1
Start Page 73
End Page 80
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307633
JaLCDOI 10.18926/15488
FullText URL Mem_Fac_Eng_OU_25_1_37.pdf
Author Bouzidi, Moncef| Koga, Ryuji| Wada, Osami| Kagawa, Naoki| Hai, Xu| Kosaka, Megumi| Sano, Hiroya|
Abstract Is proposed a tunable diode laser absorption spectrometer system which employs a pulsed current to drive the diode laser still implementing a second-harmonic detection methods enhancing a signal to noise up to 104 times that the case without it. This system affords the lead-salt diode laser a higher operating temperature which allows a more compact deep cooling system. A principle is based on employing a gated integrator between the preamplifier and the lock-in amplifier. Investigations are made on the optimum selection of the gating aperture time interval as determined by response time of the infrared detector and the pulse width of the laser driving current.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1990-12-14
Volume volume25
Issue issue1
Start Page 37
End Page 50
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307549
JaLCDOI 10.18926/15495
FullText URL Mem_Fac_Eng_OU_24_2_31.pdf
Author Oka, Hisao| Isayama Yoshiharu| Nakauchi Makoto| Yamamoto, Tatsuma|
Abstract A small vibration on the body surface is expected to apply to a clinical examination of the autonomic nervous system. The vibration cannot be found by the naked eyes. It is called a microvibration (MV) or a minor tremor (MT). It is not cleared out why and how the MV occurs, but many papers about its occurrence and clinical application have been published. In this study, the typical spectrum of MV and the various causes of MV occurrence are studied. The relationships of MV with heart rate, muscle contraction and MV are discussed. The power spectrum of MV is obtained by using an autoregressive model.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1990-03-29
Volume volume24
Issue issue2
Start Page 31
End Page 40
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307725
JaLCDOI 10.18926/19591
FullText URL Mem_Fac_Eng_OU_31_2_21.pdf
Author Oka, Hisao| Nakamura, Takahiko|
Abstract In evaluating the stiffness of skin surface, internal structures such as bone and muscle often affect the measurements. In the present paper, acoustic random vibration is used to estimated the viscoelasticity of a silicone-gel model. This viscoelasticity, which includes two different stiffness strata, is first estimated using a mechanical impedance spectrum, which describes the relation between the depth and viscoelasticity of internal objects. This method is applied to the depth of a silicone-gel tumor model measured by ultrasound imaging and the viscoelasticity of internal gel can be accurately estimated.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1997-03-28
Volume volume31
Issue issue2
Start Page 21
End Page 27
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002309105
JaLCDOI 10.18926/19592
FullText URL Mem_Fac_Eng_OU_31_2_29.pdf
Author Oka, Hisao| Ohshima, Masakazu|
Abstract Knee replacement arthroplasty is indicated for the patient with advanced knee pain, knee deformation, and knee functional disorder. The aim of this study was to estimate loosening after a knee replacement arthroplasty. Loosening is measured by a frequency response function, and mobility by random vibration. The modal parameters for the knee joint are obtained by applying a modal analysis to the frequency response function. The values decrease as the knee joint prosthesis loosened. These parameters serve as an index for the condition between a thighbone and the prosthesis. The various indexes will greatly clarify the stage of advance in the loosening of knee-joint prostheses.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1997-03-28
Volume volume31
Issue issue2
Start Page 29
End Page 37
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002309172
JaLCDOI 10.18926/19634
FullText URL Mem_Fac_Eng_OU_32_15.pdf
Author Mori, Masahiro| Oka, Hisao|
Abstract In a stiffness estimation of living body, an internal structure under the skin influences the measured results. Because a different stiffness of body caused by bones and muscles is obtained. In this paper, by using a measurement system of mechanical impedance, the relations between a viscoelasticity and a distance from the surface of silicone-gel model is calculated. This relation is applied to silicone-gel tumor model and a shape and a viscoelasticity of semi-sphere silicone-gel tumous are estimated. The obtained results are expressed as a reconstructed 3-D image of shape / viscoelasticity. The revised curve-fitting of mechanical impedance and the cancellation of peripheral vibration influence are proposed in order to increase an estimation acccuracy.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1998-04-20
Volume volume32
Issue issue1-2
Start Page 15
End Page 22
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002309047