JaLCDOI 10.18926/47029
フルテキストURL mfe_36_2_083_089.pdf
著者 Watanabe, Tetsushi| Wada, Osami| Koga, Ryuji| Toyota, Yoshitaka| Miyashita, Takuya|
抄録 Suppression of common-mode current is important to achieve electromagnetic compatibility of high-speed and high-density electronic circuits. The authors have focused on the common mode current flowing on a printed circuit board (PCB) to explain the excitation mechanism. A narrow ground pattern in microstrip structure excites common-mode current. In the previous paper, the authors explained the mechanism of common mode generation by means of "current division factor" for simple PCBs. The estimated radiation from a simple PCB agreed well with measured one. In this paper, the authors extend the theory to be applied to generalize ground structure. The validity of the theory is confirmed by comparing the measured radiation and the estimated value using the common-mode model for a test PCB. The estimated radiation agrees well with the measured one within 3 dB up to 900 MHz.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 2002-03
36巻
2号
開始ページ 83
終了ページ 89
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120003497051
JaLCDOI 10.18926/14086
フルテキストURL Mem_Fac_Eng_OU_41_1_63.pdf
著者 金谷 健一| 菅谷 保之|
抄録 The convergence performance of typical numerical schemes for geometric fitting for computer vision applications is compared. First, the problem and the associated KCR lower bound are stated. Then, three well known fitting algorithms are described: FNS, HEIV, and renormalization. To these, we add a special variant of Gauss-Newton iterations. For initialization of iterations, random choice, least squares, and Taubin’s method are tested. Numerical simulations and real image experiments and conducted for fundamental matrix computation and ellipse fitting, which reveals different characteristics of each method.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 2007-01
41巻
1号
開始ページ 63
終了ページ 72
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002308585
JaLCDOI 10.18926/17833
フルテキストURL Mem_Fac_Eng_OU_43_27.pdf
著者 東辻 浩夫|
抄録 When the Coulomb coupling between fine particles becomes sufficiently strong in fine particle plasmas, the isothermal compressibility of the whole system diverges and we have a phase separation and an associated critical point. Experimental conditions of fine particle plasmas, densities and temperatures of components and the fine particle size, are obtained corresponding to characteristic parameters around the critical point and the dependency on ion species and other factors is discussed.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 2009-01
43巻
開始ページ 27
終了ページ 31
ISSN 1349-6115
言語 English
論文のバージョン publisher
NAID 120002308947
JaLCDOI 10.18926/15384
フルテキストURL Mem_Fac_Eng_OU_30_1_99.pdf
著者 Wang, Ming| 和田 修己| 古賀 隆治|
抄録 A cylindric mirror was used, in place of a parabolic mirror, to collimate the crescent blue laser beam radiated from the Cerenkov SHG in channel waveguide configuration. The cylindric mirror radius is requested to be twice the focal length of the parabolic mirror. The focusing effect of the cylindric mirror in collimation can be compensated by slightly lifting the mirror in its normal direction. Under the condition that the mirror was declined by 5.56° and lifted by 25 μm, we got the collimated beam with divergence angle less than 1.3 mrad. In the focusing experiment, the collimated beam was focused with spotsize of 1.8 μm. The details on the analysis and experiment are reported.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 1995-12-28
30巻
1号
開始ページ 99
終了ページ 110
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002307418
JaLCDOI 10.18926/15438
フルテキストURL Mem_Fac_Eng_OU_28_1_61.pdf
著者 竹下 祐二| 河野 伊一郎|
抄録 Knowledge of the unsaturated soil hydraulic properties is essential requirement for prediction of seepage flow and contaminant transport through the vadose zone. Unfortunately, these parameters are usually time consuming and expensive to measure in the field and laboratory. At the present condition, there are few data accumulation for Japanese soils. In this paper, van Genuchten's closed-form expressions are described to estimate unsaturated soil hydraulic properties. To evaluate the adequacy of these expressions, comparisons are performed between observed and calculated unsaturated hydraulic properties for typical Japanese soils.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 1993-11-30
28巻
1号
開始ページ 61
終了ページ 69
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002307801
JaLCDOI 10.18926/15419
フルテキストURL Mem_Fac_Eng_OU_29_2_49.pdf
著者 Ahmed, Anis| Taniguchi, Shinji| 和田 修己| Wang, Ming| 古賀 隆治|
抄録 For weakly guiding dielectric waveguides, the eigenmode field distributions are calculated numerically with a simple algorithm. In this numerical method, the transverse sampling space can be chosen arbitrarily, and hence a narrow waveguide can be analyzed. The field satisfying scalar wave equation is expressed by the discrete Fourier transform and the mode eigenvalues and eigenfunctions are calculated by solving an eigenvalue equation numerically. The validity of this method is checked for 2-D waveguides having step and parabolic or square index distributions. It is found that for the well guided TE modes of the slab waveguide, the accuracy of this method is remarkably good, but some discrepancies are found if the mode is near cut off. In the problems where the normalized guide index b is small, caution should be taken in applying the results of this numerical method.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 1995-03-27
29巻
2号
開始ページ 49
終了ページ 55
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002307858
JaLCDOI 10.18926/47003
フルテキストURL mfe_36_1_091_106.pdf
著者 Kanatani, Kenichi| Ohta, Naoya|
抄録 We present a theoretically optimal linear algorithm for 3-D reconstruction from point correspondences over two views. We also present a similarly constructed optimal linear algorithm for 3-D reconstruction from optical flow. We then compare the performance of the two algorithms by simulation and real-image experiments using the same data. This is the first impartial comparison ever done in the sense that the two algorithms are both optimal, extracting the information contained in the data to a maximum possible degree. We observe that the finite motion solution is always superior to the optical flow solution and conclude that the finite motion algorithm should be used for 3-D reconstruction.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 2001-12
36巻
1号
開始ページ 91
終了ページ 106
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120003497029
JaLCDOI 10.18926/47002
フルテキストURL mfe_36_1_079_090.pdf
著者 Kanatani, Kenichi|
抄録 We first present an improvement of Kanatani's subspace separation [8] for motion segmentation by newly introducing the affine space constraint. We point out that this improvement does not always fare well due to the effective noise it introduces. In order to judge which solution to adopt if different segmentations are obtained, we present two criteria: one is the standard F test; the other is model selection using the geometric AIC of Kanatani [7] and the geometric MDL of Matsunaga and Kanatani [13]. We test these criteria doing real image experiments.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 2001-12
36巻
1号
開始ページ 79
終了ページ 90
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120003497028
JaLCDOI 10.18926/46968
フルテキストURL mfe_37_1_011_014.pdf
著者 Totsuji, Chieko| Limant, Muhammad S.| Tsuruta, Kenji| Totsuji, Hiroo|
抄録 A theoretical approach which has been successful in reproducing results of molecular-dynamics simulations on dusty plasmas is applied to estimate the screening length and the electric charge of two-dimensional dust crystals of melamine particles in the discharge chamber experiment. It has been found that the screening length is of the same order of magnitude as the inter-particle distance and the electric charge decreases on increasing number density of dust particles.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 2002-11
37巻
1号
開始ページ 11
終了ページ 14
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 80015784816
JaLCDOI 10.18926/15393
フルテキストURL Mem_Fac_Eng_OU_30_2_15.pdf
著者 岡 久雄| 藤原 史朗|
抄録 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.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 1996-03-29
30巻
2号
開始ページ 15
終了ページ 20
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002307965
JaLCDOI 10.18926/19592
フルテキストURL Mem_Fac_Eng_OU_31_2_29.pdf
著者 岡 久雄| 大島 正和|
抄録 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.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 1997-03-28
31巻
2号
開始ページ 29
終了ページ 37
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002309172
JaLCDOI 10.18926/19591
フルテキストURL Mem_Fac_Eng_OU_31_2_21.pdf
著者 岡 久雄| 中村 貴彦|
抄録 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.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 1997-03-28
31巻
2号
開始ページ 21
終了ページ 27
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002309105
JaLCDOI 10.18926/46979
フルテキストURL mfe_37_2_045_060.pdf
著者 Xu, Wei| Zhao, Y.| Horikane, T.| Hayata, T.| Tosuji, H.| Kagawa, Y.|
抄録 Resistivity distribution sounding of the non-homogeneous earth is important for electrical ground system design, geophysical prospecting and survey or monitoring the groundwater flow level. The previous paper presented that the direct inversion of the electric resistivity distribution in a domain is possible from the impedance data measured over the domain boundary using the dual reciprocity boundary element modelling in two-dimentional field [1]. The proposed inversion technique is extended to the distribution in three-dimensional space [2]. This technique is capable of inversion without iteration and meshing of the domain. Electric field with spatially varying conductivity is governed by Laplace equation, which is transformed into a Poisson-type expression with an inhomogeneous term involving the conductivity difference as a source term. Dual reciprocity method (DRM) is a technique for transforming the domain integral associated with the inhomogeneous term in Poisson equation into the boundary integral expression. The resistivity distribution in the field can thus be identified from the data observed over its boundary, for which some examples are demonstrated [2]. In this paper, the examination is extended to the case where only the data measured over the single surface is used for the inversion.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 2003-03
37巻
2号
開始ページ 45
終了ページ 60
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 80016037881
JaLCDOI 10.18926/15415
フルテキストURL Mem_Fac_Eng_OU_29_2_29.pdf
著者 岡 久雄| 福田 敬|
抄録 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.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 1995-03-27
29巻
2号
開始ページ 29
終了ページ 37
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002307199
JaLCDOI 10.18926/15359
フルテキストURL Mem_Fac_Eng_OU_34_19.pdf
著者 Okada, Akira| Uno, Yoshiyuki| Okajima, Isao|
抄録 In EDM, the machining characteristics greatly depend on the energy distribution. Therefore, it is very important to clarify the energy distribution for understanding various phenomena in EDM. In this paper, the energy distribution in EDM with graphite electrode is investigated by measuring the temperatures of electrode and workpiece. Experimental analysis shows that the material removal rate depends on energy density while the electrode wear greatly depends on the adhesion of heat resolved carbon from machining fluid, and the energies distributed into electrode and workpiece are almost constant regardless of pulse duration.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 2000-03-27
34巻
1-2号
開始ページ 19
終了ページ 26
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002307707
JaLCDOI 10.18926/15383
フルテキストURL Mem_Fac_Eng_OU_30_1_89.pdf
著者 東辻 千枝子| Sanaka Yoshiaki| 東辻 浩夫|
抄録 Based on the tight-binding method, electronic bands of the mixed perovskite oxides are calculated in order to develop the electronic theory of ferroelectric phase transitions in these mixtures which are difficult to describe within the phenomenological theories. Diagonal elements of Hamiltonian matrix of parent materials are assumed to differ by 0.1eV and mixtures are simulated by lattices of supercells containing 2(3) = 8 or 3(3) = 27 unit cells randomly assigned to either material. The width of the conduction and valence bands have maxima and the band gap has a minimum at intermediate mixing ratio. Results are in agreement with those of other analyses on random systems and even 2(3)-cell computation seems to serve as a first approximation for our purpose.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 1995-12-28
30巻
1号
開始ページ 89
終了ページ 97
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002307957
JaLCDOI 10.18926/20011
フルテキストURL Mem_Fac_Eng_OU_29_1_7.pdf
著者 Hiroyuki Tachibana| 東辻 浩夫| 奈良 重俊| 東辻 千枝子|
抄録 Effects of interface fluctuations on the electronic states in semiconductor quantum dots are analyzed on the basis of numerical solutions for ground state wave functions and energy eigenvalues. It is shown that the effective volume of confinement becomes smaller than the real volume of quantum dots due to fluctuation. This effect comes from the fact that the wave functions with larger characteristic wavelength are not able to deform themselves following the fluctuation of interfaces exactly.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 1994-11-30
29巻
1号
開始ページ 7
終了ページ 14
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002310741
JaLCDOI 10.18926/15395
フルテキストURL Mem_Fac_Eng_OU_27_1_65.pdf
著者 奈良 重俊| Hara Yuji| 東辻 浩夫|
抄録 Quantum mechnical electron wave transfer between two quantum wires which are weakly coupled via a thin potential barrier is considered. The total electronic states are calculated with both analytical ( no field case ) and numerical methods ( under applied electric fields ). The transfer efficiency is evaluated for several specified cases of geometrical structures, potential barrier heights and the externally applied electric field. Estimated trasfer time is of the order of one picosecond in typical mesoscopic structures. The model in this paper can be used to determine important structure parameters for experiments on electron directional coupler controled by external elctric field.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 1992-11-25
27巻
1号
開始ページ 65
終了ページ 79
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002307405
JaLCDOI 10.18926/14150
フルテキストURL Mem_Fac_Eng_39_1_46.pdf
著者 門野 恵典| 東辻 千枝子| 鶴田 健二| 東辻 浩夫|
抄録 We present a real-space, polynomial-expansion approach to electron dynamics in nanostructured semiconductors. The Chebyshev expansion method is employed for efficient calculation of timeevolution of single-electron wave function. Details of the formulation are described. The method is applied to the electron transport in nanostructured semiconductors such as Si nanowires. The mean-square displacement and diffusivity of electron in Si chains are obtained as functions of length of the chains. The results show clearly ballistic behavior of electron in the pure Si chain.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 2005-01
39巻
1号
開始ページ 46
終了ページ 51
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002308231
JaLCDOI 10.18926/19962
フルテキストURL Mem_Fac_Eng_OU_44_73.pdf
著者 Imanaka, Hiroyuki| Tanaka, Soukichi| Feng, Bin| Imamura, Koreyoshi| Nakanishi, Kazuhiro|
抄録 We used modified Czapek-Dox (mCD) or dextrin-peptone-yeast extract (DPY) media to cultivate a filamentous fungus, Aspergillus oryzae IAM 2706 by three different cultivation methods, i.e., shaking-flask culture (SFC), agar-plate culture (APC), and membrane-surface liquid culture (MSLC), to identify the differences in cultivation behaviors and gene transcriptional profiles. The fungi cultivated by APC or MSLC secreted a greater number of different proteins/enzymes in larger quantities compared with fungi cultivated by SFC, particularly when DPY medium was used. In particular, the amounts of protease secreted by fungi cultivated via MSLC or APC were much greater compared with SFC. When mCD medium was used, α-amylase activity was barely detectable in all cultures while the activity was detected in MSLC and APC in a quantity that was several times higher than that in SFC using DPY medium. SDS-PAGE analysis and N-terminal amino acid sequences confirmed 6 proteins in the culture supernatants when DPY medium was used. Among these proteins oryzin (an alkaline protease) and α-amylase were detected at much higher levels in APC and MSLC compared with SFC, which was consistent with the measured activity of the secreted enzymes. However, when mCD medium was used, only oryzin was detected in significant amounts in MSLC and APC. Microarray analyses of the fungi cultivated by SFC, APC or MSLC using either mCD or DPY media indicated that the gene transcriptional profile of the MSLC sample was similar to that of the APC sample but different from that of the SFC sample. When mCD medium was used, most of the genes that were up-regulated 10-folds or greater in the MSLC sample relative to the SFC sample were unknown or predicted proteins. Transcription of the oryzin gene was only slightly up-regulated in the MSLC sample while transcription of the α-amylase gene was slightly down-regulated. On the other hand, when DPY medium was used, many known genes including the oryzin gene were up-regulated in the MSLC sample versus the SFC sample.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 2010-01
44巻
開始ページ 73
終了ページ 83
ISSN 1349-6115
言語 English
論文のバージョン publisher
NAID 120002309053