| JaLCDOI | 10.18926/19953 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_44_1.pdf |
| Author | Nagai Shinji| Umeda Ryosuke| Tsuruta, Kenji| |
| Abstract | In this paper, we investigate a light-confinement phenomenon in the structure which has triangular latice composed of Double NeGative Metamaterial (DNGM). In geometrical optics consideration, this structure is expected to confine lights completely by sequential refractions in the structure. We demonstrate it by using the two dimensional finite-difference time-domain simulations. We introduce Drude-Lorentz model for dielectric and magnetic dispersion of the material at optical frequencies. We analyze quantitatively the effects of energy loss in the DNGM on the light-confinement efficiency. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 2010-01 |
| Volume | volume44 |
| Start Page | 1 |
| End Page | 6 |
| ISSN | 1349-6115 |
| language | English |
| File Version | publisher |
| NAID | 120002309117 |
| 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 | English |
| File Version | publisher |
| NAID | 120002309019 |
| JaLCDOI | 10.18926/19955 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_44_13.pdf |
| Author | Kanatani, Kenichi| Sugaya Yasuyuki| |
| Abstract | A new numerical scheme is presented for computing strict maximum likelihood (ML) of geometric fitting problems having an implicit constraint. Our approach is orthogonal projection of observations onto a parameterized surface defined by the constraint. Assuming a linearly separable nonlinear constraint, we show that a theoretically global solution can be obtained by iterative Sampson error minimization. Our approach is illustrated by ellipse fitting and fundamental matrix computation. Our method also encompasses optimal correction, computing, e.g., perpendiculars to an ellipse and triangulating stereo images. A detailed discussion is given to technical and practical issues about our approach. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 2010-01 |
| Volume | volume44 |
| Start Page | 13 |
| End Page | 23 |
| ISSN | 1349-6115 |
| language | English |
| File Version | publisher |
| NAID | 120002309170 |
| JaLCDOI | 10.18926/19956 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_44_24.pdf |
| Author | Kanatani, Kenichi| Sugaya Yasuyuki| |
| Abstract | We present an improved version of the MSL method of Sugaya and Kanatani for multibody motion segmentation. We replace their initial segmentation based on heuristic clustering by an analytical computation based on GPCA, fitting two 2-D affine spaces in 3-D by the Taubin method. This initial segmentation alone can segment most of the motions in natural scenes fairly correctly, and the result is successively optimized by the EM algorithm in 3-D, 5-D, and 7-D. Using simulated and real videos, we demonstrate that our method outperforms the previous MSL and other existing methods. We also illustrate its mechanism by our visualization technique. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 2010-01 |
| Volume | volume44 |
| Start Page | 24 |
| End Page | 31 |
| ISSN | 1349-6115 |
| language | English |
| File Version | publisher |
| NAID | 120002309159 |
| JaLCDOI | 10.18926/19957 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_44_32.pdf |
| Author | Kanatani, Kenichi| Niitsuma Hirotaka| Sugaya Yasuyuki| |
| Abstract | We present an alternative approach to what we call the “standard optimization”, which minimizes a cost function by searching a parameter space. Instead, the input is “orthogonally projected” in the joint input space onto the manifold defined by the “consistency constraint”, which demands that any minimal subset of observations produce the same result. This approach avoids many difficulties encountered in the standard optimization. As typical examples, we apply it to line fitting and multiview triangulation. The latter produces a new algorithm far more efficient than existing methods. We also discuss optimality of our approach. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 2010-01 |
| Volume | volume44 |
| Start Page | 32 |
| End Page | 41 |
| ISSN | 1349-6115 |
| language | English |
| File Version | publisher |
| NAID | 120002309124 |
| JaLCDOI | 10.18926/19958 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_44_42.pdf |
| Author | Kanatani, Kenichi| Rangrajan Prasanna| |
| Abstract | This paper presents a new method for fitting an ellipse to a point sequence extracted from images. It is widely known that the best fit is obtained by maximum likelihood. However, it requires iterations, which may not converge in the presence of large noise. Our approach is algebraic distance minimization; no iterations are required. Exploiting the fact that the solution depends on the way the scale is normalized, we analyze the accuracy to high order error terms with the scale normalization weight unspecified and determine it so that the bias is zero up to the second order. We demonstrate by experiments that our method is superior to the Taubin method, also algebraic and known to be highly accurate. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 2010-01 |
| Volume | volume44 |
| Start Page | 42 |
| End Page | 49 |
| ISSN | 1349-6115 |
| language | English |
| File Version | publisher |
| NAID | 120002309054 |
| JaLCDOI | 10.18926/19959 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_44_50.pdf |
| Author | Kanatani, Kenichi| Niitsuma Hirotaka| Rangrajan Prasanna| |
| Abstract | We present highly accurate least-squares (LS) alternatives to the theoretically optimal maximum likelihood (ML) estimator for homographies between two images. Unlike ML, our estimators are non-iterative and yield solutions even in the presence of large noise. By rigorous error analysis, we derive a “hyperaccurate” estimator which is unbiased up to second order noise terms. Then, we introduce a computational simplification, which we call “Taubin approximation”, without incurring a loss in accuracy. We experimentally demonstrate that our estimators have accuracy surpassing the traditional LS estimator and comparable to the ML estimator. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 2010-01 |
| Volume | volume44 |
| Start Page | 50 |
| End Page | 59 |
| ISSN | 1349-6115 |
| language | English |
| File Version | publisher |
| NAID | 120002308986 |
| JaLCDOI | 10.18926/19960 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_44_60.pdf |
| Author | Nogami, Yasuyuki| Morikawa, Yoshitaka| |
| Abstract | This paper proposes a method for generating a certain composite order ordinary pairing–friendly elliptic curve of embedding degree 3. In detail, the order has two large prime factors such as the modulus of RSA cryptography. The method is based on the property that the order of the target pairing–friendly curve is given by a polynomial as r(X) of degree 2 with respect to the integer variable X. When the bit size of the prime factors is about 500 bits, the proposed method averagely takes about 15 minutes on Core 2 Quad (2.66Hz) for generating one. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 2010-01 |
| Volume | volume44 |
| Start Page | 60 |
| End Page | 68 |
| ISSN | 1349-6115 |
| language | English |
| File Version | publisher |
| NAID | 120002309063 |
| JaLCDOI | 10.18926/19961 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_44_69.pdf |
| Author | Nekado, Kenta| Kato, Hidehiro| Nogami, Yasuyuki| Morikawa, Yoshitaka| |
| Abstract | Recently, pairing–based cryptographies have attracted much attention. For fast pairing calculation, not only pairing algorithms but also arithmetic operations in extension field should be efficient. Especially for final exponentiation included in pairing calculation, squaring is more important than multiplication. This paper proposes an efficient squaring algorithm in extension field for Freeman curve. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 2010-01 |
| Volume | volume44 |
| Start Page | 69 |
| End Page | 72 |
| ISSN | 1349-6115 |
| language | English |
| File Version | publisher |
| NAID | 120002309070 |
| JaLCDOI | 10.18926/19962 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_44_73.pdf |
| Author | Imanaka, Hiroyuki| Tanaka, Soukichi| Feng, Bin| Imamura, Koreyoshi| Nakanishi, Kazuhiro| |
| Abstract | 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. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 2010-01 |
| Volume | volume44 |
| Start Page | 73 |
| End Page | 83 |
| ISSN | 1349-6115 |
| language | English |
| File Version | publisher |
| NAID | 120002309053 |
| JaLCDOI | 10.18926/20011 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_29_1_7.pdf |
| Author | Hiroyuki Tachibana| Totsuji, Hiroo| Nara, Shigetoshi| Totsuji, Chieko| |
| Abstract | 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. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 1994-11-30 |
| Volume | volume29 |
| Issue | issue1 |
| Start Page | 7 |
| End Page | 14 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002310741 |
| JaLCDOI | 10.18926/20012 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_29_1_15.pdf |
| Author | Totsuji, Chieko| Matsubara, Takeo| Obuchi, Masumi| |
| Abstract | A molecular orbital approach to the electronic structure of C(60) molecule is formulated on the basis of optimized bond orbital model and the stability of the truncated icosahedron structure is examined. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 1994-11-30 |
| Volume | volume29 |
| Issue | issue1 |
| Start Page | 15 |
| End Page | 22 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002310919 |
| Author | Faculty of Engineering, Okayama University| |
|---|---|
| Published Date | 2004-03 |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Volume | volume38 |
| Issue | issue1-2 |
| Content Type | Others |
| JaLCDOI | 10.18926/46946 |
|---|---|
| FullText URL | mfe_38_1-2_001_004.pdf |
| Author | Sakakibara, Akira| Kanadani, Teruto| |
| Abstract | The relationship between occurrence of serration and reversion heat treatment was studied by tensile test on Al-10mass%Zn alloy. Serration was observed for the furnace cooled specimen, but not for the as-quenched one and the shortly aged one, which result is difficult to be interpreted by the Cottrell theory. The stress amplitude in the serration increased with increasing the time of annealing for reversion up to 10ks and then stayed at a constant value which might be interpreted by the Cottrell theory. The stress amplitude in the serration decreased with increasing the annealing temperature, which is contrary to the prediction by the Cottrell theory. The specimen directly annealed without aging and the one annealed after aging agreed well with each other in the tensile strength and the stress amplitude in the serration, which suggests solute clusters as the cause of serration. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 2004-03 |
| Volume | volume38 |
| Issue | issue1-2 |
| Start Page | 1 |
| End Page | 4 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 80016785932 |
| JaLCDOI | 10.18926/46947 |
|---|---|
| FullText URL | mfe_38_1-2_005_014.pdf |
| Author | Ishimaru, Kazuhito| Konishi, Masami| Imai, Jun| Nishi, Tatsushi| |
| Abstract | Temperature distribution in the reactor furnace is mainly operated by gas blowing from multiple tuyeres and material charge distribution. The objective of our research is obtain the optimal profile of gas flow to control temperature distribution in the reactor furnace in the shortest possible time. We formulated the optimization problem to reduce deviation of temperature distribution from its desired one in the reactor furnace. Based on the formulation, gas blow conditions are optimized by a sequential quadratic programming method to realize the desired temperature distribution. The validity of the method was checked through numerical experiments. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 2004-03 |
| Volume | volume38 |
| Issue | issue1-2 |
| Start Page | 5 |
| End Page | 14 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 80016785933 |
| JaLCDOI | 10.18926/46948 |
|---|---|
| FullText URL | mfe_38_1-2_015_027.pdf |
| Author | Torigoe, Takashi| Konishi, Masami| Imai, Jun| Nishi, Tatsushi| |
| Abstract | In these days, mechanical systems are becoming more complex and highly automated. So, there exist wide variety of demands for reliable diagnostic technology. A reliable data analysis and quantitative diagnosis method of mechanical system is necessary for the purpose. In this paper a quantitative diagnosis method for looper height control system has been developed based on neural network technologies. The wavelet transformation is used for pre-processing to analyze characteristics of looper height control system. And, self organizing map neural network is used for the purpose of classification based on the pre-processed data. After that, the classified results are used for quantitative diagnosis in hierarchical neural network. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 2004-03 |
| Volume | volume38 |
| Issue | issue1-2 |
| Start Page | 15 |
| End Page | 27 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 80016785934 |
| JaLCDOI | 10.18926/46949 |
|---|---|
| FullText URL | mfe_38_1-2_029_032.pdf |
| Author | Totsuji, Hiroo| Totsuji, Chieko| Ogawa, Takafumi| Tsuruta, Kenji| |
| Abstract | The structure of dust particles in dusty plasmas under microgravity has been analyzed by molecular dynamics simulation. The charge neutrality condition satisfied by the system composed of dust particles and ambient plasma is properly taken into account. It is shown that dust particles form shell structures at low temperatures and the number of shells are obtained as a phase diagram in the plane of two parameters characterizing the system: the number of particles and the strength of screening. It is also shown that these structures are almost independent of the strength of screening. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 2004-03 |
| Volume | volume38 |
| Issue | issue1-2 |
| Start Page | 29 |
| End Page | 32 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 80016863328 |
| JaLCDOI | 10.18926/46950 |
|---|---|
| FullText URL | mfe_38_1-2_033_037.pdf |
| Author | Liman, M. Sanusi| Totsuji, Chieko| Tsuruta, Kenji| Totsuji, Hiroo| |
| Abstract | The dynamic structure factor and the spectrum of the momentum-density fluctuations of 2D Yukawa liquids are analyzed in the domain of weak and intermediate coupling and screenlng parameters. The dispersion relations of the longitudinal and transverse collective excitations are obtained and compared with the random phase approximation (RPA) and harmonic approximation for triangular lattice. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 2004-03 |
| Volume | volume38 |
| Issue | issue1-2 |
| Start Page | 33 |
| End Page | 37 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 80016863329 |
| JaLCDOI | 10.18926/46952 |
|---|---|
| FullText URL | mfe_38_1-2_039_059.pdf |
| Author | Kanatani, Kenichi| |
| Abstract | We investigate the meaning of "statistical methods" for geometric inference based on image feature points. Tracing back the origin of feature uncertainty to image processing operations, we discuss the implications of asymptotic analysis in reference to "geometric fitting" and "geometric model selection", We point out that a correspondence exists between the standard statistical analysis and the geometric inference problem. We also compare the capability of the "geometric AIC" and the "geometric MDL' in detecting degeneracy. Next, we review recent progress in geometric fitting techniques for linear constraints, describing the "FNS method", the "HEIV method", the "renormalization method", and other related techniques. Finally, we discuss the "Neyman-Scott problem" and "semiparametric models" in relation to geometric inference. We conclude that applications of statistical methods requires careful considerations about the nature of the problem in question. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 2004-03 |
| Volume | volume38 |
| Issue | issue1-2 |
| Start Page | 39 |
| End Page | 59 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 80016889442 |
| JaLCDOI | 10.18926/19654 |
|---|---|
| FullText URL | Mem_Fac_Eng_OU_33_2_9.pdf |
| Author | Yamamoto, Kyoji| |
| Abstract | The molecular dynamics study is applied for interaction of the gas molecule with the solid wall to analyse the flow of a rarefied gas between two wall. The wall consisting of Pt molecules is considered to be in a state of physical adsorbates. Two problems are considered : one is the flow problem and the other is the temperature problem. It is found that the tangential momentum accommodation coefficient is about 0.8 when the relative speed ratio of the two walls is unity, while it decreases with increasing Knudsen number when the relative wall speed ratio is 5.0. It shown that the temperature accommodation coefficient is about 0.85 at 300K wall, 0.75 at 450K wall, and 0.69 at 600K wall. |
| Publication Title | Memoirs of the Faculty of Engineering, Okayama University |
| Published Date | 1999-04-27 |
| Volume | volume33 |
| Issue | issue2 |
| Start Page | 9 |
| End Page | 17 |
| ISSN | 0475-0071 |
| language | English |
| File Version | publisher |
| NAID | 120002309121 |
